A LETTER, &c. (continued 2)

At the time the Birmingham Railway was before Parliament last session, maps of it were issued from the office of that company, which gave the “Section of the line of railway; shewing the rises and falls.”

This section is on too small a scale to shew either the height of the embankments or the depth of the cuttings: and though it has not suited my convenience to spare the time necessary for examining the section deposited in Parliament, yet as the cubic yards of cuttings and embankments amount to nearly twenty-three millions: as the map and section I have just mentioned shew ten tunnels (some of which are a mile and upwards in length): and inclined planes, in unbroken rises of 6, 8, 10, 11, 13, 20, and 25 miles, there can be no doubt but that much deep cutting and high embanking is included in it. Now though I do not mean to imply that the expense of all cutting and embanking could have been saved, by taking proper advantage of the power of ascending heights, which is imparted by the momenta of the velocities whereat locomotive engines now go, yet I do mean to state it as my full conviction, that had this railway been (as the second prospectus of the Liverpool and Manchester Railway, stated that line should be) “laid down and arranged with that skill and conformity with the rules of mechanical science, which will equally challenge approbation, whether considered as a national undertaking of great public utility, or as a magnificent specimen of art” the whole of the anticipated expenses of deep cutting and high embanking would have been expunged from the estimates; it being certain, that deep cuttings, high embankments, and long inclined planes are no more evidences of engineering skill, than winning a battle by hard fighting is of generalship: while the expense of the numerous “very small cuttings varying from 8 to 10 feet,” which are spoken of in the “Minutes of Evidence taken before the Lords’ Committees,” might as certainly have been saved, and those rises passed over by the vehicles in consequence of their momentum; as a cricket ball will roll over a mole-hill.

But if these remarks are applicable to the Birmingham Railway—the line of which, was I believe, laid out in 1831—what must be said relative to the now proposed London and Bristol Railway?

For nearly twelve months the principle of avoiding level, and constructing “undulating railways” has been discussed, in consequence of Mr. Badnall having taken out a patent for, and published a work, proposing such “undulating railways”: and though, owing to the fall on your line being wholly (as well as greatly) one way, it is not necessary to express any opinion here on a proposition, which appears to have for its object the construction of unlevel railways in preference to level ones, and the labour of toiling up hill for the sake of the momentum to be obtained by running down hill, yet as, in consequence of it, the effect of momentum in carrying moving bodies up ascents, has been largely and widely adverted to for the last twelve months (nearly), it must have been within the expectation of every one, that, let the gentleman who has been employed to lay out the line of the Bristol Railway be anxious as he might, to avoid any “undulating” proposition, he would be equally anxious to call in the aid of all known and established principles, to diminish the expense of the line he was required to lay down. [32]

Now, nothing, I believe, is more certain, than that if a vehicle be moving along a level at the rate of 2¾ (2.7272) miles an hour, it will, on coming to an inclined plane, and provided the operation of the power which overcame friction on the level, be continued, so as to neutralise and (as relates to counteractive effect) annihilate friction during the ascent, “swing” itself up, and rise to the height of (that is, its momentum will cause it to rise to the height of) three inches perpendicular; let the angle of ascent, or rate of rise of the plane, be what it may.

Equally certain is it, that if the velocity of the vehicle be twice 2¾ miles an hour, that is 5.4544 miles, the momentum will (under similar circumstances as to counteraction of friction) then cause the vehicle to rise up said inclined plane to four times the height to which the former velocity raised it; or to the height of one foot. And it is equally certain, that the momenta imparted by increased velocities will, under the circumstance of the friction of the vehicle being overcome, neutralised, and (as relates to counteractive effect) annihilated, by the continued operation of the moving power during the ascent, cause the vehicle to rise up any inclined plane to the perpendicular heights stated in the following table:—

Carriages moving on levels, at the under-mentioned velocities, the motions of which are changed from horizontal to ascending, by means, either of circular or angular ascents. Have momenta, which (friction being counteracted and neutralised) will cause them to rise to the under-mentioned heights (perpendicular) above the level where those velocities were attained: let the rate of rise, or angle of ascent, be what it may.

MILES. MILES PER HOUR. PERPENDICULAR.

2¾ or 2.7272 3 inches.

5½ or 5.4544 1.0 foot.

11 or 10.9088 4.0 feet.

22 or 21.8176 16.0 do.

44 or 43.6352 64.0 do.

88 or 87.2704 256.0 do.

176 or 174.5404 1024.0 do.

352 [33] or 349.0808 4096.0 do.

Now, let it have been proper as it may, that the gentleman whose name appears as “Engineer” to the Bristol Railway, should (in laying out that line) have avoided encumbering the subject with the “undulating” question, there can be no doubt that it was incumbent on him to diminish expense in every way which established principles admitted. And as the usual railway rate is now 20 miles an hour, while that rate will give momentum enough to cause any vehicle to rise up any inclined plane to the height of 13⅓ feet (perpendicular) above the level on which it was running at the rate of 20 miles an hour, it is necessary only to lay out the line of this railway in levels, and rises of 10 feet each, to avoid (very nearly, if not quite) all necessity for cutting, or embanking; while deep cutting, high embanking, and tunnelling, might (except in very peculiar cases) have been as certainly avoided, as erecting a suspension bridge will obviate the necessity for piers and arches over a river. Yet does not this gentleman appear to have any more called in the aid of this law of motion, than did those equally “eminent engineers” who laid out the line of the Liverpool and Manchester Railway; or those who have laid out that of the Birmingham Railway: the “Report” of the public meeting held at Bristol, on the 30th July last, stating that “although the line of country (except for about 30 miles at the Bristol end) is very advantageous, yet the comparative levelness of the railway will be attained by a great deal of deep cutting, and several tunnels;” while the prospectus issued from the London office of the Company states, that “the construction of a road so nearly level, in the hilly country about Bath and Bristol, will, unavoidably, be a costly work.”

The length of the Birmingham Railway is 112½ miles; that of the Bristol Railway “from 115 to 118 or 120 miles,” average 117½. The estimated expense of the cuttings, embankments, and tunnels, of the Birmingham Railway is 429,286l. or 3,185l. per mile. The same expense on the Bristol Railway is (835,300l. + 15,000l.=) 850,300l. or 7,236l. per mile; that is, above twice as much: and this too, notwithstanding that the Report states that “this expensive part of the work, fortunately, lies principally in two of the most favourable materials—the chalk and the freestone;” and also notwithstanding that the estimate of the Birmingham Railway has undergone two years’ scrutiny, and the most rigid investigation, by several Parliamentary Committees; while that for the Bristol Railway is the result of only a “preliminary survey,” directed by a “Provisional Committee:” so that were it to be increased as the estimate for the Birmingham Railway has been increased, it would be many times as much as the similar work on that railway. Indeed, the parties themselves have made a considerable increase already: 10 per cent. being added to the above amount of 850,300 by the Bristol Committee, and 7 per cent. by the London Committee; [34a] so that 978,494l. is the whole amount at present allowed for works, which taking proper advantage of the momentum of the vehicles would have saved.

Yet, with well-known laws of motion thus set at nought and neglected, and with expense thus unnecessarily as well as most enormously added to, are the Committee—gentlemen who were, unavoidably, as entirely dependant on the opinion of their engineers, as the Ministry of 1789 were upon that of the “Insanity Doctors,” relative to the mental affliction of George III.; or as those of 1830 were on that of the physicians who attended George IV. during his long illness—under circumstances of such entire dependence on the opinion of their engineers, are the “Provisional Committee” of the Bristol Railway led into the following expressions of approbation in their Report: “The Committee think it but justice to say, that the zeal, the diligence, the ability and other valuable qualities manifested by these gentlemen, have given them ample reason to congratulate themselves on their choice”!; and “The Committee, in conclusion, repeat that they have carefully availed themselves of the resources of skill and experience in investigating the probable cost of the railway.” [34b]

Now as, were I to presume to manifest “skill, experience, ability, and other valuable qualities,” such as these, with respect to your line, or thus to throw away, not only hundreds of thousands, but also half millions, on any other, I should be sure to experience the truth of that proverb, which says that merely looking over the hedge shall subject one man to the operations of “the finisher of the law,” while another man may steal the horse with impunity, I must avail myself of this law of motion, which “skill, ability, experience, and other valuable qualities” so neglect and despise, to get loads up the rise which you wish to surmount, without resorting to deep cutting or high embanking.

Sixty feet of the rise to be surmounted, occurring in the last half-mile of your line, I shall have nearly two miles to acquire the necessary velocity in: and as the continuation of the action of the power which overcame friction on the level, will neutralise, and, as relates to counteractive effect, annihilate the friction of the carriages while ascending these sixty feet, I have only to cause them to attain a velocity somewhat greater than has yet been attained on railways, that is, 42½ miles an hour during the two miles, to enable them to “swing” themselves up these sixty feet, in consequence of the momentum which that velocity will impart: while, let the height of Rodway Hill (which is adverted to as so desirable to avoid, in the Report of the Provisional Committee of the Bristol Railway) be what it may, all that would be requisite to obviate the necessity for the “inclined plane and stationary engine” spoken of as unavoidable there, would be to attain the velocity due to the altitude of said hill, to enable my vehicles to surmount it from their momentum.

Nor would the ascending power imparted by the vertical operation of the pressure of the atmosphere, be much less important with respect to diminishing the expense of bridging, on the line of this Bristol Railway, than would “momentum” as relates to the expense of cutting and embanking. From the map issued from the London office of that Company, it appears that that railway is to be carried five times across the Avon; twice across the Kennet and Avon Canal; three times across the Wilts and Berks Canal; and four times across the Thames. These various crossings are not for the sake of approaching places of magnitude, or commercial importance; but solely because the principle of railway transmission compels the level to be servilely adhered to: while, though the right line distance between London and Bristol is only 108 miles, yet is the line of railway there laid down, shewn as being 120 miles long; the 12 additional miles being added by the curves taken in thus crossing these waters for the sake of the level.

Now though I do not mean to say that it would be possible, by laying down a tunnel instead of this railway, to avoid all bridging whatsoever, yet owing to hills and rises being no impediment to the operation of this principle, the line for a tunnel might be several miles shorter than this line of the railway, and yet the whole of these bridges be saved, excepting one over the Avon; while not a quarter of the expense would be incurred for carrying a tunnel over the waters which its course must cross, which will be incurred in bridging the railway over those other waters that intersect its course, which are not laid down in the map shewing its line.

The estimated expense of bridging for the railway is 474,800l.; which, when increased by the per centages allowed by the Committees, amounts to 556,194l. as the whole estimated expense of bridging. What proportion of this amount is for bridging over waters, and what for bridging over roads, is not stated. On the Liverpool and Manchester Railway 108,565l. 11s. 9d. was expended on 63 bridges; of which only five were over waters: the other 58 being over roads, or to carry roads over the railway. On the Birmingham Railway the number of bridges is 300; of which only nine are stated to be over waters, the others being for roads. The estimated amount of them is 350,574l. One bridge alone (the Sankey viaduct) on the Liverpool and Manchester line, cost nearly 50,000l.

Now as the power of going up or down, imparted by the vertical operation of the pressure of the atmosphere, would render it wholly immaterial whether the level was preserved in the line of a tunnel; as burying it under ground, in the manner proposed at page 27, would equally do away with any occasion for the many hundreds of bridges, which, on the three lines I have mentioned, must be provided to carry those railways clear of roads, as it would save bridging over the roads on your line; and as a tunnel could have been carried under the Sankey, for almost one-tenth of the expense it cost to construct the viaduct by which the Liverpool and Manchester Railway is carried over that canal—as my principle offers facilities of this kind for obviating the necessity of bridging—I do not hesitate to say, that, on the whole three lines, and considering how much the actual, will exceed the estimated amounts, above one million sterling might be saved in the item of bridging alone, by substituting tunnels for railways; which, when added to, as it would be, by the almost equal amount that would be saved in the expense of the land, in consequence of my plan requiring a width of only ten or a dozen feet under ground, instead of from 60 to 300 on the surface, will admit of my saying that (in round numbers) nearly two millions might be saved by my plan, in these two items of bridging and land, on the lines of the Liverpool and Manchester, the London and Birmingham, and the London and Bristol Railways: while, if what my plan would save of the 398,286l. allowed for the cost of land, and of the 261,928l. allowed for that of the entrances to London, Bath, and Bristol, be added to the savings I have stated it would effect in bridging, cutting, embanking, and tunnelling, I may say that it would also save nearly two millions (of the present estimated expense) on the Bristol Railway alone.

The ten times greater heights than I have yet specified, which may be surmounted by combining the operation of the momentum of the air itself with that of the vehicles, it is not necessary for me to trouble you with, owing to the shortness of your line, and the small height to be ascended: though it may be permitted me to observe, that as attaining only equal velocities to those which have been spoken of as attainable by locomotive engines and steam-coaches, will enable my vehicles, of themselves, to surmount hills of many hundred feet in height; while combining with their momentum, the momentum of the air itself (that which is before the vehicles; the friction whereof will be overcome, and neutralised by the operation of the exhausting apparatus) in tunnels of proper length, and loads of corresponding weight, will enable me to ascend more thousands of feet, than the momentum of the vehicles alone will carry them up hundreds, I may be able to extend Louis le Grand’s exclamation, “Il n’y a plus des Pyrennées,” to “il n’y a plus des montagnes sur la terre,” so far as relates to their longer preventing intercourse between countries; and consequently render the whole earth level to us, in point of effect.

In reference to the force required to overcome the friction of the medium by which the moving power operated to impel the carriages, would a tunnel be also superior to a railway. From Messrs. R. Stephenson and Locke’s reply to Mr. Walker’s Report to the Directors of the Liverpool and Manchester Railway, it appears that the friction of the ropes by which stationary engines draw waggons up inclined planes, is one-twelfth of their weight: while, as the latter part of your line gives a sharper rise than that of the Liverpool tunnel, the weight of the rope you must use should not be less than 7lbs. per yard; the friction and gravitation of which would be 0.73231b. per yard, or 1289lbs. per mile. The line in the plan for the railway, which was laid before your meeting, being 2½ miles long, the whole resistance of friction and gravitation upon it would be 3222 lbs.

From experiments on the friction of air in tubes, I am enabled to state that both the inertia and friction of the air against the inside of an equal length of the tunnel I propose to you to lay down would not, when said air was moved by exhaustion, and conveying 50 tons at the same rate at which the same quantity is drawn up the tunnel of the Liverpool and Manchester Railway (i.e. ten miles an hour), be so much as one sixteenth part of this; while it would have this important advantage, that the heavier the load was, the less would be both the inertia and friction of the air. For instance: the degree of exhaustion requisite to admit of an equal load to what is drawn up the Liverpool tunnel (i.e. 50 tons) being moved up a tunnel of the same size as that I constructed at Brighton, and rising at the same rate your’s must rise (1 in 47) by the pressure of the atmosphere, would be about the 40th part of a vacuum.

But supposing ten times this load were to be raised, the degree of exhaustion must be ten times as great, or about the fourth of a vacuum. And, as the greater the exhaustion, the less the expansive power, and, consequently the less the inertia and friction of the air inside the exhausted part of the tunnel, this “rope of air” as it has, derisively, been called, possesses the important advantage of decreasing as relates to the density, inertia, and friction, which itself opposes, in proportion to the increase of the load drawn by it: while, as the valves I should place at every quarter, or half, or whole mile, to be opened by the carriages as they pass them, and admit air immediately behind said carriages, would prevent there being the inertia and friction of more than a few hundred yards of air of the natural density behind the carriages to be overcome, the impediment which presents an insuperable obstacle in the opinion of the numbers who have condemned the proposition (because they deemed operating by exhaustion the same as operating per plenum) diminishes, in point of fact, to a far less important hindrance, than that which is occasioned by the old system of drawing loads by means of stationary engines and ropes; since, in the present instance, the inertia and friction would not be the one-hundred-and-sixtieth part of what it would be, to move an equal quantity by the stationary engine, and rope system.

And notwithstanding that the superiority which the tunnel possesses over the locomotive system is not so great at this, yet is it important.

In the instructions given to Mr. Walker by the Directors of the Liverpool and Manchester Railway (and which called from him the Report criticised by Messrs. R. Stephenson and Locke), it is stated that “the quantity of traffic for which it will be expedient to provide the power of conveyance” is about 4000 tons, from each to the other of those places, daily.

In his publication on the Liverpool and Manchester Railway, Dr. Lardner says, “In the experiments which I have detailed, it appears that a steam engine is capable of drawing 90 tons at the rate of about 20 miles an hour; and that it could transport that weight twice between Liverpool and Manchester in about three hours.” [38a] The weight of this engine alone being 8.1 tons, the whole weight of itself, and its tender, with the necessary supplies of fuel and water, will not be less than twelve tons. Therefore, the friction of the engines (and their tenders) requisite to carry these 4000 tons at the rate of 20 miles an hour, would be 4267 lbs.

The friction of one mile of air in a tunnel eight feet in diameter, when moved at the rate of 20 miles an hour by exhaustion being 288lbs., the friction of it in a tunnel extending from Liverpool to Manchester, will be 8640lbs.: which, though double the friction of these locomotive engines, might be far cheaper for the following reason; and independent of the circumstance, that I could lay down a tunnel capable of carrying all these 4000 tons at one and the same time, from Liverpool to Manchester, for one-fourth of what that railway has cost; [38b] and also independent of the circumstance that the enormous expense now incurred for the repairs of the locomotives (as stated on page 11) would also be saved.

It is well known that the smaller a steam-engine is, the larger is the proportionate quantity of fuel it requires, and the greater the proportionate expense of working it; while it is equally well known that, owing to the imperative importance of lightness and efficiency over economy in locomotive engines, this disadvantage increases in a most rapid ratio with respect to them. In consequence of this, a quantity of fuel, which, in large stationary engines, such as I should use for exhausting air from the tunnel, would do a given quantity of work, would, in the best of the locomotives on the Liverpool and Manchester Railway, do only one-sixteenth as much work.

Therefore it results, that, notwithstanding the friction of the air in a tunnel 30 miles long would, at the rate of 20 miles an hour, be twice as much as the friction of the locomotive engines, yet, owing to the fuel consumed by the latter, to move themselves and their tenders, being sixteen times as great as large stationary engines, such as I should use, would require to do the same work, the tunnel would, supposing the whole quantity of goods were to be carried at once, be eight times the cheapest mean of conveyance, in point of current expenses only, and without reference to its first cost being only one-fourth that of the railway; and also without reference to the whole of the enormous expense now occasioned by the repairs of the locomotive engines being saved.

But this is not the only proportion in which a tunnel might be cheaper. The 13th paragraph of the Russian Engineer Officer’s Report, states, that he is “convinced that exhaustion to a degree which should give a pressure of fifteen inches of mercury may be effected in the tunnel.” Now, notwithstanding that much more than this may be done in an iron tunnel, yet will I calculate on this only. Fifteen inches of mercury being 7.3 lbs. that pressure on the area of the tunnel, would move above twice the 4000 tons which the Directors of the Liverpool and Manchester Railway estimated would be carried from one to the other of those places every day; which, supposing that weight to be conveyed at one time, would reduce the expense (per ton of goods carried) of overcoming the friction of air moving in a tunnel from Liverpool to Manchester, at the rate of 20 miles an hour, to one-sixteenth of what the power required to overcome the friction of the locomotive engines required to draw the same weight would cost.

And though, owing to its being a received opinion that the power required to overcome the friction of fluids increases according to the square of the velocity, we are to suppose that at 40 miles an hour, the fuel required to overcome the friction of the air would be one-fourth that of the locomotive engines, while at 80 miles an hour it would be equal to that of the engines, still would a quadruple velocity be attained, by the expenditure of only an equal quantity of fuel.

The amount of the power required to overcome the friction of the locomotive engines (and their tenders) necessary to carry 4000 tons weight from Liverpool to Manchester daily, at the rate of 20 miles an hour, is, when expressed in “horse’ power” equal to the power of 225 horses working for an hour and a half. In other words, these locomotives must exert power to this amount, beyond what is required to draw the 4000 tons weight.

The power required to overcome the friction of air, which was moving (by exhaustion) at the rate of 20 miles an hour, in a tunnel of eight feet diameter, extending from Liverpool to Manchester, would be equal to that of 456 horses: which, though double the preceding, would yet be eight times cheaper, owing to large stationary engines, such as I should use, requiring only one-sixteenth part of the fuel required by locomotives to do equal work.

At 40 miles an hour (supposing locomotives could go so fast) the number of horses’ power required to overcome the friction of the air in the tunnel would (according to the received opinion of that friction increasing to the square of the velocity) be 3650: which, though sixteen times greater than that of the locomotive engines and their tenders, yet, in consequence of this power being exerted only for three-quarters of an hour, instead of an hour and a half, and of fuel doing sixteen times as much work in large stationary engines as in locomotives, would be only half so expensive as the locomotives and their tenders would prove.

At 80 miles an hour (which is twice as fast as locomotives can go) the power required to overcome the friction of the air in the tunnel, would (on the calculation that it increases according to the square of the velocity) be equal to that of 29,196 horses; which is nearly 130 times as much as the locomotive engines would require: though, owing to this power operating only 22½ minutes, instead of an hour and a half, and to fuel in large stationary engines doing sixteen times as much work as in locomotives, the expense would be only twice as great as in the locomotives, exclusive of the whole of the most enormous expense now incurred, by the repairs of the locomotives being saved (which would, alone, more than make up the difference) and also exclusive of the tunnel costing only one quarter of what the railway has cost, and of the rate of conveyance being four times as fast.

But it is not with respect to a tunnel only, that the resistance of the air opposes an impediment: this resistance being found so serious an obstacle to the progress of the locomotive engines and their loads, that in all trials of, or experiments with them, the state and direction of the wind is noted and allowed for. In the “Account of the Liverpool and Manchester Railway,” published by the Treasurer of that Company (H. Booth, Esq.), he says: “Moreover, at great velocities, the resistance of the air must not be left out of the calculation. At ten miles per hour, it has been found by experiment, that the resistance of the atmosphere is about half a pound weight on a square foot of flat surface; at fifteen miles, the resistance is 1lb. per square foot; and at twenty miles, about 2lbs. per square foot: the increased resistance being, nearly, as the squares of the velocities.” [40]

The surface opposed to the air by a steam-coach, the engines of which its proprietor told me were equal to ten horses power, I found to be 30 square feet. That, opposed by another, the engines of which were said to be equal to twenty horses power, I found to be above 50 square feet: while, when carrying four outsides on the front of the roof, this coach exposed nearly 70 square feet to the action of the air. The surface opposed to the air by the large locomotive engines now used on the Liverpool and Manchester Railway, I understand (when chimney, axle-tree, wheels, and every thing that cuts the air, is taken into account) to be about 40 feet square. Supposing it to be so, at 20 miles an hour, the air will oppose resistance equal to 80lbs. to the progress of the engine; which resistance having to be overcome at the rate of 1760 feet per minute, is equal to 4¼ horses power. At 40 miles an hour, this resistance would be 320lbs.; which resistance having to be overcome at the rate of 3526 feet per minute, would be equal to 34 horses power. At 80 miles an hour, the resistance of the air would be 1280lbs.; which resistance, having to be overcome at the rate of 7,040 feet per minute, would be equal to 270 horses power; while at 100, and 120 miles an hour, the power required would be, respectively, that of 528 and 912 horses.

Now, as the force required at 80 miles an hour, is a few times more than the whole power of those engines, and as Dr. Hutton found that giving the moving body the form of a cone, the height of which equalled the diameter of its base, diminished the resistance of the air only half, it may serve to shew that the statements of those who have given currency to the opinion that we may be conveyed at any velocity on railways, are promulgated by persons who pronounce upon questions without examining them: since, in addition to this resistance of the air to the locomotive engines themselves, would be its resistance to the tenders, and coaches or waggons they drew; and that, too, independent of, and additional to, the resistance opposed by the railway friction of the engines, tenders, and loads, behind them.

That something of this kind prevents very high velocities from being attained on railways, is evident. At the locomotive engine competition on the Liverpool and Manchester Railway four years ago, velocities of from 35 to 40 miles an hour, were attained by engines which were not one-tenth the power of some of those now used; while, at the opening of that railway, three years ago, the engine by which the surgeon was brought to Mr. Huskisson, after his deplorable accident, went 15 miles in 25 minutes, which is at the rate of 36 miles an hour. Yet do not the so much more powerful locomotives now used on that road, go faster than this: a circumstance which may prove that the limit to the velocity of railway conveyance, will arise from a source not calculated on.

“But,” it may be observed, “this objection to the possibility of very high velocities on railways, is counterbalanced by the dilemma in which you place yourself, by supposing it to be possible that any such power as that of 29,196 horses, can, at one time, be made to operate on a tunnel; since, as relates to practical application, it would prove ‘an impossible quantity.’”

The inference I deny; and, when necessary, will disprove. [41] But the term I accept; and will avail myself of, to shew that it is equally “an impossible quantity” that even if a tunnel were ten times as long as one between Manchester and Liverpool, the friction of air which is caused to move in it, in consequence of exhaustion taking place at the opposite end, can ever oppose an impediment such as is here adverted to.

According to the opinion that the friction of the air would increase as the square of the velocity, the friction of the column of air, which, when moved by exhaustion at the rate of 20 miles an hour, in a tunnel eight feet diameter and a mile long, was 288lbs., would, when moved at the rate of 80 miles an hour, be 4608lbs.; which, on the whole area of the tunnel, would be equal to 1.3 inches of mercury. Therefore, supposing that at every mile of a tunnel extending from Liverpool to Manchester, barometer tubes were to be inserted, the bottoms (or basin ends) of which should be open to the atmosphere, and the tops open to the inside of the tunnel, the mercury in each successive tube would (reckoning towards the end at which the exhaustion took place) rise 1.3 inches higher than that in the preceding.

Now as 1.3×23 gives 30, while 1.3×30 gives 39, it appears that at 23 miles from that end of the tunnel at which the atmosphere was admitted, and seven from that where the exhaustion took place, there would be such a vacuum as would raise mercury the whole height of the barometric column; while, at the end of the 30 miles there would be—or rather ought to be, according to this calculation—39 inches of mercury; or a vacuum and a third; which, in addition to its being “an impossible quantity,” places those who contend that the resistance of the friction of air which is caused to move through a tunnel by the pressure of the atmosphere in consequence of exhaustion taking place at the opposite end, increases according to the square of the velocity, in the dilemma of assuming that there is a certain place in a tunnel 30 miles long, where, notwithstanding that a man, a horse, or even an elephant, might walk as freely and unobstructedly along, as a mouse could through a rat-hole, that subtle, permeating, and all-pervading element which we breathe, would, like the stream of the Jordan when under the influence of the miracle by which the Israelites passed over that river, stop, stick fast, and be unable to move farther; a position, which necessarily throws us for an escape from this dilemma, on the conclusion that, though it is certain that the friction of air against the inside of the tunnel will be an impediment, and though it is probable that this impediment will be of some importance, yet must it be equally certain that it will not be the serious impediment which it is supposed it will prove: and it may therefore, safely be assumed, that the objection which presents an insuperable obstacle in the minds of the many who have condemned the method of operation by exhaustion which I propose (because they deemed it analogous to operating per plenum) becomes removed, and is found to be what all the other “insuperable objections” which have been arrayed against the proposition are found to be when grappled with; i.e. baseless and unreal: it being necessary only to put a valve at every half, or quarter of a mile, which should be opened by the carriages as they passed, to render the length of the column of air of the natural density, which must be behind the carriages to drive them along, only a few hundred yards, and its friction consequently unimportant; said valves being (as can easily be done) so arranged, as to close themselves again the moment the carriage had arrived at, opened, and passed by, the next succeeding one.

But though I freely admit that the friction of the air against the inside of the tunnel may waste power to a degree which shall prove not unimportant, yet may it be doubted whether it will be more important than the waste of power occasioned by the present method of railway transmission by locomotive engines.

In the documents laid before the Lords’ Committees on the London and Birmingham Railway, by the Treasurer of the Liverpool and Manchester Railway, on the 28th June, 1832, it is stated that the “number of trips of thirty miles” performed (or travelled) by the locomotive engines between Liverpool and Manchester, in the half year ending the 31st December, 1831, was “5392”: which, as the same document shews that the whole amount of profitable weight conveyed over those 30 miles during that half year was less than 91,000 tons, gives an average of only 17 tons as the profitable weight carried each “trip.” The weight of the engines by which these loads were drawn it may be difficult to fix upon: though, as the locomotives now used on that railway, are, some of them, above six tons, others above eight, and others above ten tons in weight, it may, perhaps, be fair to take eight tons as the average weight. The weight of the tenders with fuel and water, appears to be rather a delicate subject. The weight of the tender of the Rocket, with its load of fuel and water, at the grand locomotive engine competition in October, 1829, was three-fourths that of the engine itself. There have since been many accounts of immense loads drawn on the railway, of which those by Dr. Lardner, in his “Lectures on the Steam Engine,” are considered as “by authority.” But though we find the weights of the engines, as well as of the loads, and various other particulars (even to the state of the wind) given, yet does it happen that the weights of the tenders, with their supplies of fuel and water, are “unascertained” and omitted, throughout. Under these circumstances, I can do no other than act on the best information I have obtained, and suppose the weight of the engines and tenders with their cargoes of fuel and water to be twelve tons for each “trip.”

Assuming it to be so, the weight of the moving power will be above two-thirds of the profitable weight conveyed; while, supposing the same proportion to obtain as to the 4000 tons just mentioned, the amount of the effect of the friction of the power by which they were conveyed at the rate of 20 miles an hour, would be twice and a half as much as the friction of the air would be in a tunnel when twice the tonnage was conveyed from Liverpool to Manchester in it, at the same rate; which, for equal quantities, is five times the friction while, as relates to the fuel consumed, it would be very many more times than this, dearer.

There is one class, who, above all others, might derive benefit from properly considering what I thus submit, relative to the friction of the air.

When what was termed “the railway mania” was at its height, it was calculated that no body of men would be so much benefited by it as the iron trade; in proof of which the following statement was circulated:—

“We are authorised to state, that the rail-roads already projected, will require considerably more than two millions of tons of iron. Now, as iron has recently advanced from 7l. to 14l. per ton, it appears that the iron masters (by the way, the originators of, or principals in, many of these schemes) will receive from the subscribers twenty-eight millions sterling.”

But, instead of the iron trade having been benefited by the principal portion of what is expended on railways being for their article, scarcely more than one-twentieth-part has been expended for iron; the remainder having gone for labour in “cutting and embanking,” &c. &c.

In the account in Mr. Treasurer Booth’s book, of the expenses of the Liverpool and Manchester Railway, the line which, in the statement, runs “Iron rail account,” gives only 66,830l. as paid to the iron masters: the other hundreds, which make up the aggregate of 67,912l. there mentioned, being for “oak plugs, freights, und cartages;” which is little more than one-twentieth part of the whole that has been expended on this railway.

The rails of the London and Birmingham Railway are to be half as heavy again as those of the Liverpool and Manchester Railway. Yet does the expense of the “rails, chairs, keys, and pins,” in the estimate of that railway laid before Parliament, amount to only 212,940: one twelfth, that is, of the two millions and a half, which form the aggregate of the estimate there given in.

One of the inducements which railway advocates have held out to the landed proprietors of the Houses of Parliament, in order to lead them to support railway bills, has been the degree to which poor rates, &c. would be diminished, in consequence of the labourers there would be employed in digging out the earth for the cuttings and embankments, in the different parishes through which the lines of railway would run; and in the papers of the end of June and the beginning of July (1832) is a very long advertisement of the London and Birmingham Railway Company, one part of which states that “The landed interest will be benefitted by the expenditure of upwards of two millions of the capital of the Company in labour.”

According to their own shewing, therefore, the expenditure for the benefit of the landed interest will be “upwards of two millions,” while the cost of the iron rails, &c. will be only upwards of two hundred thousand pounds. And as both this, and other advertisements, and the evidence before Parliament, announce the extension of the railway from Birmingham to Liverpool, when this first half of it from London to Birmingham is done—which extension will be about the same length as this first half—the statements of the railway advocates themselves, give the iron masters to see, that the result of the time, trouble, and expense, which they (the iron masters) have devoted to bring forward railways, is, to put more than a shilling into the pockets of the agricultural interest (by the degree to which they will save parish rates, &c. &c.) for every farthing they put into the pockets of the iron masters themselves; all that is saved to country parishes, being actual gain to the agricultural interest; while the 12th or 16th paid to the iron trade is for value in iron; out of which the usual trade profit is all that the iron masters will gain. In other words, about four millions sterling will be paid for the parishes between London and Liverpool, in the shape of wages for labourers, while only about four hundred thousand pounds will be paid to the iron masters for the iron rails, &c.; out of which the iron masters will have to pay the wages of their men who smelt &c. the iron, and the royalties (or rent) for the ore, coal, &c. &c. used in making it.

The difference there is in the specific gravities of ore, coal, and limestone, in different places, will render any estimate not correct for every place; though, generally speaking, I believe it may be received that the quantity of iron stone, coal, and lime stone, which it is necessary to raise to produce a ton of pig iron, will be about 6½ cubic yards.

In the evidence laid before the Lords’ Committees upon the London and Birmingham Railway, it is stated that the whole amount of “earth work” required for that railway, amounts to 22,779,431 cubic yards; of which a detailed statement is given in the minutes of evidence.

Dividing the twenty-three (nearly) millions of cubic yards of “earth work” which are to be excavated and embanked on the Birmingham Railway, by the number of cubic yards of ore, &c. which it is necessary to dig to make a ton of iron, will show, that if the wages which will be paid for levelling on that railway, were to be expended in digging iron ore, &c. the nation would be benefitted by having three millions and a half tons of iron more than it now possesses; while the labour expended on the railway will be not only worth nothing to the nation, but also worse; insomuch as it appears by the evidence before the Lords’ Committees that it will render 1250 acres of land, which are now cultivated and productive, sterile as a turnpike road.

It is supposed by Mr. Treasurer Booth, in his book on the Liverpool and Manchester Railway, that three thousand miles of rail-road, will, eventually, be laid down in England.

Supposing these 3000 miles to require “earth work” (cuttings and embankments, i.e.) in the same proportion that the London and Birmingham Railway will do so, and also supposing that the wages which will be paid to the Irish, &c. labourers, who do the digging for this “earth work,” were, instead, to be paid to the workmen of the iron masters for raising ore, &c. &c. and converting it into iron, the nation would be richer by nearly one hundred million tons of iron, than it will be if these said wages are paid merely for “cutting and embanking” for railways.

Now though I do not mean to insinuate that this hundred million tons of metallic worth, would increase what is now termed the “monetary wealth” of the nation, yet, as surely as their ignorance (and consequent want) of iron, rendered Mexico and Peru such easy conquests to the iron of the Spaniards, as to make them most striking examples of the truth of Solon’s warning to Crœsus, “He who has more iron, will soon be master of all this gold,” so surely would the possession of this hundred million tons of iron, be enormously more advantageous to the nation, than the cuttings and embankments required for these 3000 miles of railway will be.

Although iron be not, at the present day, either with ourselves, or in any other part of the world, the symbol of value, medium of exchange, and money, which Lycurgus made it in Sparta, when that state was in her glory, yet has it, as a commodity which will obtain us the gold and silver of Mexico and Peru in exchange for it, a value, which will procure us the amount of its worth in those metals, as certainly as any other commodity that we export. In whatever proportion, therefore, this hundred million tons of iron would procure us either the gold or silver, the corn and flour, the silks and cottons, the wines and wools, the tea and coffee, the sugar and spices, &c. &c. of other countries, would devoting the wages which will be expended in cutting and embanking for these 3000 miles of railway, to the raising and smelting of iron ore, be more valuable to the nation at large, than if so employed.

Nor is this all; since the substitute I propose for railways, would give us food for one hundred thousand people, which these railways will deprive us of.

The documents laid before the Lords’ Committees, state, that this Birmingham railway will cover and throw out of cultivation, 1250 acres of land. Supposing the proportion thrown out by the 3000 miles of railway to be the same, the whole amount will be 33,333 acres. Allowing these acres to produce three quarters of corn each, is no very excessive allowance. [45] And each individual of the kingdom being estimated to consume a quarter of corn every year, here is land that would produce bread for one hundred thousand people thrown out of cultivation by the railway system.

Now as, in addition to its being perfectly practicable for my tunnels to be buried underground, it would be decidedly best for themselves, and for the operation of the principle, that they should be so; and as ploughing, sowing, reaping, mowing, and all other operations of agriculture, may go on over them, as over any drain, or water-pipe, there is, in addition to the metallic difference which my plan would make to the riches of the nation, the circumstance, that, besides providing this exchangeable metallic wealth, or exportable value, it would also provide us, every year, with food for one hundred thousand more people, than the railway system can provide for.

The metallic part of the question being, however, that which concerns the iron trade, I will keep to that.

One of my early views of this method of conveyance, was, that it might prove important to the iron trade, from the much greater quantity of their production which it would consume, than railways require: and it has, for these seven years, been an object with me, to awaken the attention of the iron masters to (as I conceived) its importance to them, and to endeavour to convince them of the propriety of giving to a plan, which would consume tons of their article, where railways consume only hundred weights, the same fostering and support which they gave to bringing forward railways.

But it has not pleased the iron masters to see the case in the same light in which it presented itself to me.

It is well known to them, that in the year 1810 we had neither a steam-vessel nor a gas-work in the kingdom: the propositions to adopt both those important inventions being then termed and treated, just as this proposition of mine is now termed and treated, i.e. as “impossible, absurd, and madness to think of.” Yet have they seen that a sum of (roundly speaking) ten millions, has, since that period, been sunk in the construction of gas-works and steam-vessels.

With proofs such as these before them (and which have led to the consumption of so much of their production as gas-works and mains require), that, what they, a few years ago, deemed utterly impossible, may, nevertheless, be quite the reverse—it might have been supposed that the iron masters would not prove, either incredulous to, or bigoted against, the belief that a still more important extension of the use of their article was about to open to them.

But, to my great surprise, I have found, that of all unbelievers, the iron masters have proved the most unbelieving.

Other people doubted only because the want of knowledge on the subject, which they openly avowed, left them no alternative. But, in the iron masters, I have had “to contend with the pride of false knowledge.” The world at large said, “We cannot believe, because we cannot understand.” But the iron masters say, “We do not believe, because we know better.”

On asking them how and why they “knew better,” I found that it was not, as some might suppose, from any doubt or difficulty as to the tunnel itself; which they admitted could be cast and laid down, of any size or dimensions that might be required. Neither was it from any doubt as to steam-engines or air-pumps being large and powerful enough to do what was necessary;—the tens of thousands of gallons of air ejected per minute, from the air-pumps which they use to blow the fires of their smelting-furnaces, and the hundreds of horses power they know steam-engines are made equal to, removing all question on these points. [46] But their incredulity arose from a difficulty which one of them had met with, in forcing air through a pipe; and of which they supposed me ignorant; but to which I had adverted, in a publication years before, in the following words:

“It is too well known, to be at all affected in point of veracity, by an inability to mention either the exact time or place, that the proprietor of an iron work in Wales had, some years ago, occasion to erect an additional furnace, at the distance (recollection states) of about three-quarters of a mile from his old ones. The blast apparatus of these old works being large enough to supply this new furnace in addition to the old ones, he conceived it would prove much cheaper, if, instead of having power and blast cylinders erected at the new work, he were to lay a pipe from the old ones, to convey to the new one the superfluous blast. This he accordingly did; and as soon as the pipe was completed, set the apparatus going, to ascertain the strength of the blast he could thus apply to the new furnace. To his great surprise, however, no blast was produced; a gentle current, which would hardly blow a candle out, being all that was perceptible. For a result so adverse to his expectation, he could account in no way but by supposing that, from accident or design, the pipe was stopped up. As the readiest way to ascertain whether it was so, he put a cat in at one end, and blocked it up, leaving her to find her way to the other.

“Thus situated, puss had no alternative but that of seeking an exit at the other end: this she accordingly did, and, contrary to his expectations, soon made her appearance there. Convinced by this that the pipe was not stopped up, he concluded that the disappointment he had experienced arose from the friction of the air against it; and finding that he could in no way obviate this difficulty, he was obliged to abandon the design, and be at the additional expense of blast apparatus for his new furnace.

“Now, had the proposition this treatise submits, been, that we should convey ourselves through a tunnel such as has been adverted to, by employing apparatus on the principle of blast furnaces, to blow us through, by forcing air in behind us, the circumstance which has just been stated would be fatal to that proposition. But when, instead of being blown through, by air forced in behind us, it is proposed to cause the air which is behind the vehicle to operate to push it forward, in consequence of some being taken from before it, the case is widely different. Air which is forced to move in a pipe, in consequence of other air being driven into that pipe behind it, operates (in degree) as a wedge, and opposes to the power which moves it, resistance, arising from becoming, as it were, wedged against the pipe, through its whole length. But air which, instead of being forced to move by an impulse from behind, that, as it were, wedges it against even the very end of the pipe it enters at, is allowed to move, owing to some being taken out from before it instead of being forced in behind it, becomes affected as any thing from which a wedge is withdrawn is affected; that is, freedom of motion is allowed, and its parts play so much more freely, that friction is diminished instead of increased. The impediment would prove, therefore, less important in this case than in the other, even were there no method of altogether obviating it; happily, however, the means of doing this are in our power. Between driving a vehicle through the proposed tunnel by forcing air in behind it, and according to the method which has been stated, there is this difference,—that in the former case the impulse can be given only from the end where the moving power operates; while, in the latter, arranging valves, which should be opened by the vehicle as it passed over them, would admit of that impulse being renewed at every hundred yards, could it be necessary to do it so frequently. Let the friction of the air against the pipe be what it may, therefore, a valve at every mile, or at every half or quarter of a mile, which (as may be done) should be opened by the vehicle as it passed along, and caused to remain open till it (the vehicle) had arrived at the next valve, would prevent any diminution of the velocity at which we might be conveyed, that would prove important.

“This reasoning may be illustrated by a figure relating to an experiment. Air was forced through a pipe 56 feet long, at the rate of 20 miles an hour, under a pressure which is equal to 2.2 inches of water; and as it required a pressure which is equal to 0.6 inches of water to make air move at that rate through a hole in the side of a vessel, there was consequently 1.6 inches greater pressure at that end of the pipe at which the air entered, than at the end from whence it issued.

“Now if the length of the pipe—the tenths of pressure at the entering—and those at the issuing end, be expressed by two lines approximating each other, as shewn below, it may be conceived how ‘air which is forced to move in a pipe in consequence of other air being driven into that pipe behind it, operates as a wedge; and opposes to the power which moves it, resistance, arising from becoming as it were wedged against the pipe, through its whole length.’”

“Since the length of these two lines bears the same proportion in hundredths of an inch to 56 feet, as the spaces between the ends of them bear (in tenths of an inch) to 2.2 inches of water, and 0.6 inches of water; [48a] and if we conceive that forcing air to move in this way, is, in some degree, analogous to drawing an elastic endless rope, the size of which should be equal to the larger end of the pipe, through it, and out at the smaller end, we may form some idea of the degree to which power would be absorbed in operating by a plenum. And not only this; since, reversing the operation, and supposing the rope to be drawn from the smaller to the larger end, will also give us some idea of the effect of operating by exhaustion, or vacuum; and enable us to conceive that ‘air which is allowed to move, owing to some being taken out from before it, instead of being forced in behind it, becomes affected, as any thing from which a wedge is withdrawn is affected; that is, freedom of motion is allowed, and its parts play so much more freely, that friction is diminished instead of increased.’”

Unconvinced, however, by arguments of this kind, the iron masters persist in maintaining what I propose to be impossible, because one of them found that the exactly reverse process is so. In other words, they act just as those “impossibleists” did, who, in their ignorance that high steam would admit of the vacuum, air-pump, ponderous condensing chest, and ton of cold water per horse power per hour, which are inseparable from low-pressure engines, being dispensed with in high-pressure engines, pronounced it to be utterly impossible ever to make steam-engines capable of running upon roads, because such engines could neither carry the ponderous apparatus inseparable from the condenser, nor the immense quantity of cold water required to produce the vacuum which, alone, renders low-pressure engines efficient.

In vain did I point out to them, not only that I had not overlooked their objection, but that my earliest views of the subject, had adverted to, and expressly guarded against it. It was of no use: for no “Demetrius” or other “craftsman” of that day ever vociferated, “Great is Diana of the Ephesians!” more perseveringly, than the principal iron masters of the present day have exclaimed in honour of the idol “Impossible,” whom it pleased them to set up and worship, in opposition to the (as they deemed it) heresy I presumed to attempt to teach them.

Had they done me the honour to prove me heretical, and that theirs was the true faith, I should have been importantly benefitted, as well as convinced: insomuch as it would have prevented me from devoting at least seven additional years of time, and all the means in my power during that period, to the subject. But when they would not trouble themselves to examine, and condemned, solely because they proclaimed “impossible,” a method of operation, which I not only did not advocate, but which my publications proved I had long and openly disclaimed, I could not but feel, first, the truth of Dr. Robertson’s observation, “As in Genoa ignorance had opposed and disappointed Columbus, in Lisbon he had to combat with prejudice, an enemy no less formidable;” and, secondly, that just as the reasoning of the pilot who was chosen to execute the treachery planned against Columbus, failed, because he had courage only to go half-way, so did the reasoning of these gentlemen fail, because they have done only half what is necessary to disprove the practicability of what I propose. [48b]

In publications, besides that just quoted, I have not only stated my conviction that the method of operation which the iron masters condemn would be impracticable, but also have endeavoured to analyse the question, and show why it would be so. But as I do not, like them, stop there, and (in effect) say that it must ever be impossible to discover a “North-West Passage,” or reach the North Pole, because Captain Cook could not get within 30° of the South Pole, these gentlemen are pleased to act the part of “Alexander the coppersmith,” against me, rather than to give themselves the trouble of examining whether the part of another Alexander might not prove more honourable, as well as more advantageous to them.

The quotation given a few pages back, states that the price of iron was raised from 7l. to 14l. in 1825, in consequence of what was then called “the railway mania.” But, so far from maintaining this price, the following extract from a Memorial, which was agreed to at a meeting of the Staffordshire Iron Trade, held at Dudley, on the 4th October, 1831, shews, that in six years the price of iron had fallen lower than ever before was known.

“Memorial to the Right Honourable Earl Grey, First Lord of His Majesty’s Treasury.

“We, the undersigned Iron Masters, of the Staffordshire Iron and Coal district, think it our duty respectfully to represent to His Majesty’s Government the following facts:

“1. That for the last five years, ever since what is called the panic of 1825, we have found, with very slight intermissions, a continually increasing depression in the prices of the products of industry, and more particularly in Pig Iron and Bar Iron, which have fallen respectively from upwards of 8l. per ton to under 3l. per ton, and from 15l. per ton to under 5l. per ton.

“2. Against this alarming and long-continued depression, we have used every possible effort in our power to make head. We have practised all manner of economy, and have had recourse to every possible improvement in the working of our mines and manufactories. Our workmen’s wages have, in many instances, been greatly reduced, and such reduction has been attended with, and effected by, very great suffering and distress:—but the royalties, rents, contracts, and other engagements, under which we hold our respective works and mines, have scarcely been reduced at all, nor can we get them effectually reduced, because the law enforces their payment in full.

“3. The prices of the products of our industry having thus fallen within the range of the fixed charges and expenses which the law compels us to discharge, the just and necessary profits of our respective trades have ceased to exist: and in many cases a positive loss attends them.

“4. Under these circumstances, we have long hesitated in determining what line of conduct our interest and our duties require us to adopt:—If we should abandon our respective trades, our large and expensive outlays in machinery and erections must be sacrificed, at an enormous loss to ourselves, and our honest and meritorious workmen must be thrown in thousands upon parishes, already too much impoverished by their present burdens, to support them:—and if we should continue our respective trades, we see nothing but the prospect of increasing distress, and certain ruin to all around us.”

The remaining part of this “Memorial” touching on politics, need not be quoted here.

If the iron of the 3000 miles of railway which Mr. Treasurer Booth, in his book on the Liverpool and Manchester Railway supposes may eventually be laid down in England, should be of the same weight which I understand that of the Birmingham Railway is to be, the whole quantity consumed will be about 800,000 tons. Supposing an equal application of the system here advocated, and that only ten times as much iron should be used in the tunnels as is used in the railways, eight millions of tons, instead of eight hundred thousand, will be the aggregate consumption.

Now as iron, though unquestionably the best, is neither the only, nor the cheapest material of which tunnels can be constructed, it may not, possibly, be unpardonably presumptuous in me to submit to the iron masters, that if they persist in doing, by this proposition, as the Genoese did by that of Columbus, they will also lose an opportunity, which would, to them, prove equally important, as would have been that of Columbus to Genoa.

I have asked, and I still ask of them only one thing: a full, and fair investigation. By the result of that I am content to abide; though I must, in common justice stipulate, that this investigation shall be entered on in a different spirit to what it has hitherto been my lot to meet with. “There is always a proneness” says Washington Irving, “to consider a man under examination as a kind of delinquent, or impostor, whose faults and errors are to be detected and exposed.” Most truly can I say that I have “always” experienced the effects of this “proneness” in reference to this subject: and that the object of those who deemed my proposition worthy throwing away a fragment of their time upon, was infinitely less to ascertain its truth and justice, than to display their own penetration and wit, in discovering and turning to ridicule, every part which admitted (as they thought) of being sneered at and made the subject of a jest.

Had it been my good fortune to have met with but one candid examinant of influence, I had been spared years of trouble and anxiety. But my proposition being deemed deserving only of contempt, candid examination has no more been vouchsafed me, than to the wanderings of a lunatic.

Should, however, the iron masters, instead of granting me this candid investigation, continue, “in the pride of half knowledge,” (as Dr. Wells terms it) to condemn what I propose, because they have found that a something has failed, which is as different from it, as would be, saying that it is impossible we can ever get to the North Pole, because Captain Cook could not get within 30° of the South, I venture to commit myself to the prediction that they will repent it, as bitterly as Genoa repented her rejection of Columbus’s proposition, to discover, and possess her of America.

“They inconsiderately rejected his proposal, as the dream of a chimerical projector,” says Dr. Robertson, of the Genoese, “and lost, for ever, the opportunity of restoring their commonwealth to its ancient splendour.”

For, equally certain as it is that iron, though the best, is not the only material of which tunnels can be constructed, is it, that unless this proposition is very differently treated by them to what it has hitherto been, will they drive the manufacturing of tunnels from their own line into another: and that, too, notwithstanding that opportunities are arising which, in addition to bringing them to their own doors, would give such facilities as relates to the transmission of the large stocks of iron which the uncertainty, and occasional long interruptions of the present method of conveyance, compel them to keep in London, as to do away with the necessity for keeping those stocks.

The Welch papers announce the plan of a railway which is to connect the iron districts and ports of that country with London. In this plan, Merthyr Tydvil, the centre of the South Wales iron manufacture, is stated to be 176 miles from London.

Now, even supposing that this railway, instead of costing the many thousands per mile which it must cost, could be laid down for nothing, still, the circumstance of the bare expenses of conveyance on the Liverpool and Manchester Railway, amounting to 4¼d. per ton, per mile, exclusive of the charges necessary to pay one farthing of interest, or return on the capital sunk in laying that railway down—and for which 3¾d. per ton, per mile, is charged, in addition to the 4¼d. required to cover the bare expenses—the mere expenses of railway conveyance, exclusive of interest or return on the capital invested, being so great as this, it appears that, even were this railway laid from their own doors to the metropolis, the iron masters could not, including the charge to pay interest or return upon the money sunk in laying the railway down, get their material to London for less than 4l. 10s. per ton; which, on an article the selling price of which (pigs) in London is only about the same amount, is in effect a prohibition; especially with the expense of freight for coast conveyance, only 12s. per ton from South Wales to London.

But as the expense of carriage by a tunnel would be as much less than this over-sea freight, as that is less than railway conveyance; while, in addition to this superiority over both, a tunnel would save all the risk as well as the delays and uncertainty of over-sea transmission, London and the iron districts might be brought within so few hours of each other, as to obviate the necessity of the iron masters keeping the heavy stocks of their article in London which they are now obliged to maintain, and the capital so locked up become, in consequence, liberated for other purposes: while, were the tunnel extended to Milford Haven, as it has been announced the railway would be, that port, as well as Swansea, might be brought within a few hours of London; and the advantages of its (perhaps) unequalled harbour, rendered fully available to the nation at large for commercial purposes, as well as to Government for our fleets.

This consideration merits the serious attention of the advocates of the Bristol Railway. Swansea and Milford Haven being both more advantageously situated for all vessels from foreign ports that would make Bristol their port of delivery; and their harbours being (particularly the latter) incomparably superior to that of Bristol, a tunnel would, were it to be laid down between either of them and the metropolis, be the certain ruin of any railway from Bristol to London. The mere expenses of carriage on the Liverpool and Manchester Railway being 4½d. per ton per mile, and the whole charge 8d., it is evident that, supposing the Bristol Railway were to cost only half what the Liverpool and Manchester has cost (the “Capital, 3,000,000l.” placed at the head of the prospectus of the Bristol Railway, allows 25,000l. per mile for each of the 120 miles the map accompanying said prospectus shews the line will be in length) the whole change for carriage along its line could not be less than 6d. per ton per mile: the aggregate of which, 3l., would be equal to what cargoes have been brought from the East Indies for; and more than equal to freights from the West Indies, Mediterranean, &c. &c.; so that only such cargoes or freights, as stress of weather drove into Bristol, would be sent to London by the railway; while, by a tunnel from Milford or Swansea, they might be sent so cheaply, as actually to command the trade which it is supposed the Bristol Railway will command.

But to return from the long digression, into which the consideration of the question relative to the effect of the friction of the air, and the importance of the subject to the iron trade, has led me.

Supposing the possibility of the Liverpool and Manchester railway proving a failure, that company would have scarcely any more saleable value in their possession, in exchange for the million and a quarter which it has already cost, and the million and a half which it will cost them, than the (about) 5000 tons of iron which is in their rails. Their long, narrow, slip of ground, dear as it has been to them, would be worth nothing; while the labour of taking up the between two and three hundred thousand stone blocks (or bases) they have laid down to carry the rails, would be more than those blocks are worth. Also would the 450,000l. expended in levelling the line and forming the road, be utterly lost. [52] Whereas, had a tunnel been laid down, not only would the whole of the hundreds of thousands expended in levelling have been saved, but as not one-tenth of the labour would have been required to lay a tunnel down, compared with what the railway required, a large sum would have been saved for that also; while what was laid out, being for metal, instead of labour, there would have been from ten to twenty times more saleable value in their hands, than they now have.

And as the same circumstances would, in a similar case, apply to the Birmingham, and Bristol (and indeed to all) Railways, as well as to your line, it would, comparatively, be almost as much better, in this particular, to have a tunnel instead of a rail-road or canal, as it would be to hold specie instead of paper, during a run on the bank: though this advantage would be greatest in relation to a canal; the greater proportion of the expense of which, is for that irrecoverable outlay, labour.

In point of the friction of the wheels would the carriages that moved in the tunnel be importantly superior to railway carriages.

Owing to circumstances which it is not necessary to discuss, the height of the wheels of the coaches and waggons on railways is confined to about three feet. Wheels of twice that diameter have been tried, but thrown aside in consequence of their liability to cause accidents by running off the rails: the only thing by which the wheels of all vehicles running on edge railways are kept on them, being a rim, which, projecting one inch beyond the bearing part of the tire of the wheels, keeps them on the rails; as the brim of a hat will keep the body of it from rising on a table, over the edge of which said brim hangs.

In consequence of this, all carriages running on open railways are liable to accidents, such as those mentioned in the notes below, many of which have occurred; though, owing to their having happened either in the excavations, on the levels, or on the low embankments, the dashings-to-pieces which will take place when they occur on the high embankments have, hitherto, been avoided. [53a]

But as the carriages inside the tunnel cannot get off the railway in it, as they do on common railways, while, owing to the constantly vertical position in which the wheels can be kept, they may be twice, or three times, as high as on common railways, so great a diminution in the power required to move any load will take place, as to admit of any weight being moved in the tunnel with less than half the power required to move it on the Liverpool and Manchester Railway.

In point of repairs, too, would the tunnel be importantly cheaper than a railway. Supposing you were to have a railway, there would be, in every mile of it, above seven thousand stone blocks, or bases, to carry the rails; every one of which bases would be liable to sink, and disarrange the level of the line, as they are so constantly doing (vide page 11); while the rails themselves would be liable to bend, and break, between these bases. Sinkings of the bases, and bendings and breakings of the rails, &c. &c. being (like fractures of the harness and apparatus of stage-coaches, or the ropes of ships) matters of constant occurrence, there are, in the whole, and including every liability to disarrangement and repair, above eighty thousand parts or places, in every mile of the Liverpool and Manchester Railway, where adjustment or repair may daily be required; while, were that railway to be made a quadruple one, by having two more lines of road (four more lines of rails, i.e.) laid down, these liabilities would increase to above one hundred and sixty thousand per mile; though, for the present, I refer only to fractures and loosenings of the chairs, &c. bendings and breakings of the rails, and sinkings, &c. of the bases, which are now possible to the amount of above 40,000 per mile; whereas, in a tunnel, the corresponding disarrangements would be possible to the amount of only 1056 per mile: an advantage which time will prove to be of much greater importance than it may at first be considered; owing to the small expense of repair it will occasion. Supposing the London and Birmingham Railway were to have the “quadruple line” adverted to when the capital was raised to three millions, there would, in its whole length, be nearly twenty millions of parts or places where repair, or adjustment, might, daily, be necessary: a number which might well double the 488l. per mile, per annum, charged under the item “Maintainance of way,” in the half-yearly accounts of the Liverpool and Manchester Railroad.

But neither is this the last circumstance with respect to which a tunnel would be superior to a railway.

From the statements laid before Parliament, it appears that in the half-year ending the 31st December, 1831, “the number of trips of 30 miles” made on the Liverpool and Manchester Railway was 5392. Now as the whole weight carried during this half-year was under 91,000 tons, it appears that the average profitable weight (passengers, or merchandise) carried each trip, was less than 17 tons.

The average weight of an engine and its tender, with fuel and water, being, I believe, not less than 12 tons, while there is the weight of the coaches and waggons additional to this, it would appear that for every ton which pays any thing, that is carried on the Liverpool and Manchester Railway, they also carry a ton which pays nothing.

Now, owing to the manner in which the carriages that move in the tunnel can be constructed, and owing to there being no locomotive engines, and tenders carrying fuel and water, required to move them, this proportion of dead and unprofitable weight will be so much reduced, as for it not to amount to more than one-fifth of the similar weight on the railway.

The whole expense of conveyance on the Liverpool and Manchester Railway during the six months ending the 31st December, 1831, was, it appears by the statement laid before the Lords’ Committees on the London and Birmingham Railway bill, fourpence farthing per ton, per mile; while the whole charge for it was eightpence per ton, per mile. Coal being nearly ten times dearer here than it is there, there is no reason to suppose that what it might cost you for conveyance along a line of railway would be less than this; while it may be presumed that it would be so much more as, perhaps, and of itself, totally to counteract the advantages afforded by the shortness of your line, compared with the present route.

In addition to the advantages which I have stated a tunnel would hold out to the Company I have the honour to address, there would be one of a peculiar nature. It is generally understood, and appears from evidence to be the fact, that a considerable portion of the income of the Liverpool and Manchester Railway Company has arisen from persons who have visited and paid for riding over their line, solely from curiosity; while it is well known that the income derived from visitors to their tunnel, by the Thames Tunnel Company, is considerable; the average annual amount having been 1200l. per annum.

The curiosity excited by the public relative to the tunnel I constructed at Brighton, surprised me. Thousands manifested a desire to see it: hundreds applied to be permitted to do so; and when they found I would not let them, offered guinea after guinea to be allowed to gratify their curiosity, under the idea that mercenary motives gave rise to the orders I left that no one should be admitted; while many of the very highest rank (including every class of our nobility) made personal application to me to oblige them with a sight of it.

As I could convey persons in your tunnel (supposing you were to have one) most safely at the rate of a mile in a minute, and as a velocity of that kind being attained near the metropolis, by a method so novel as this, would induce very many thousands to visit and ride through it for curiosity, it may be expected that a considerable part of what it would cost to lay a tunnel down would be returned from this source; enough (in the end) I am bold to say, to pay for the cost of the iron whereof it would be constructed.

The Thames Tunnel, supposing it never should be completed, will for years bring in the 1200l. per annum, which is the average of what has been received from people visiting it; and I am fully satisfied that proper measures would, in the end, bring in, from this source alone, perhaps, more than would cover the coat of the iron, of which the tunnel I propose to you would be constructed.

In the prospectus of the Greenwich Railway Company is the following paragraph:—“Moreover, when it is considered that the population of London, Westminster, and the Borough, is about one million and a half, and that the population of the surrounding towns and villages, within a circuit of from forty to fifty miles round the Capital, amounts to nearly double that number; and that, in short, the number of persons visiting London during each year, make up a total exceeding five millions of persons, it is not unreasonable to expect that, through mere curiosity alone, two millions of persons will gratify the same, when it can be accomplished at a low price, suppose only one shilling, to go and return,—yet if so, that item alone would produce 100,000l.”

Now, as supposing that the curiosity excited by my novel proposition, will produce only one quarter of what the Greenwich Railroad Company calculate may come into their pockets from the same source, will, I think, be allowing sufficient pre-eminence to the superior curiosity which an old method of conveyance must excite, I trust that my idea, that the cost of the iron composing the tunnel may be repaid from this source, will be considered a not immoderate one.

In the Thames Tunnel there is nothing but the bare arch to see; while in this there would be the tunnel itself, the largest air-pumps, &c. &c. in the world, and a ride to and fro at the rate of sixty, or more, miles an hour.

Nor would the objection which, it may be imagined, must arise from the want of daylight in the tunnel, prove an objection in point of fact. So trifling is the degree of exhaustion and pressure required to move a load of 100 tons, that, but that the advantages which would arise, as relates to cheapness of site, and evasion of opposition on the part of the land-owners and occupiers, from carrying the tunnel under ground, prevent it, I could window light the tunnel throughout its whole, length: that which I constructed at Brighton having light admitted into it through windows of common thin glass; strong plate-glass not being required. Indeed, so far as relates to possibility, the upper half of the tunnel might be one continued window (like the top of a green-house), throughout its whole length. But as, even if this was done, artificial light must be had for sixteen hours out of the twenty-four in the winter; as the tunnel might be gas-lighted throughout its whole length; or as, instead of thus wasting light unnecessarily, each carriage might carry lights before and behind, the objection that the tunnel being underground would render it dark as midnight, is no more a serious objection than it would be, were the Thames tunnel finished, that it would be better to cross the river by London Bridge, than through that tunnel, because on the bridge you would have natural, while in the tunnel you must have artificial light.

It is true that there could be no “view of the country” by this method of conveyance. But, as the object of it is the perfection of travelling, in the three particulars of safety, expedition, and economy; as even the comparatively low rates attained on the Liverpool and Manchester Railway prevent objects that are by the road-side being distinctly seen, owing to the velocity with which the passengers are whirled by them; and as the much greater velocity at which conveyance may be effected in the tunnel, would render any attempt to look on what was passed productive of the effects experienced by a child who looks on the ground while leaning out of the window of a coach, no real loss, as relates to “seeing the country,” would result from transmission taking place inside the tunnel instead of outside it: though, even if it should, it might be submitted to, when economy of both time and money, and complete obviation of the dangers attendant on breaking down, being overturned, run away with, or driven against any thing, became the equivalents.

Have we occasion to travel to Edinburgh by the mail, we unrepiningly submit to the inconvenience of passing two nights (32 hours in mid winter) not only in total darkness, but also “cabinned, cribbed, confined” to a degree which prevents us even from “changing a leg,” except by previous arrangement with our opposite fellow-passenger. But when it is proposed that we shall go in vehicles which, in addition to being as large and commodious as the cabins of many steam-vessels, will be as much shorter a time in going, as they are larger and more convenient than the inside of mail-coaches, and in which the most brilliant light may be enjoyed, we proclaim it to be “impossible” to consent to go by such vehicles, because they would move inside a tunnel: not considering that this very circumstance, of being inside said tunnel, would as certainly secure us from being overturned, driven against any thing, run away with, breaking down, or any other of the dangers to which turnpike-road travelling is liable, as it would give us the ease, comfort, and accommodations of the cabin of a steam-vessel, instead of the privations and endurances experienced in mail-coaches.

And as the valves which have been adverted to as fixed at every quarter, or half, or whole mile, would, in point of effect, be doors, by means of which exit from the tunnel could be effected, the bugbear of being “shut up in a tunnel many miles long, with no place to get out of it, if any thing should happen,” need not be seriously replied to.

Such are some of the benefits which laying down a tunnel, instead of a railway would procure you. But the most important of all is yet to be mentioned.

As it does not follow that, because you may think proper to lay a railway down, the public will think proper to use it, it becomes vital to your interest, that some inducement which shall lead them to use it, and cause them to prefer the more circuitous route to the Birmingham Railway by your line, to the more direct one by the Edgeware Road, should be laid before them. This inducement will be furnished by the tunnel which I propose to your adoption.

The carriages which would go in said tunnel, may be rendered so superior in point of size, of the room they will give to each passenger, of comfort, and of general accommodation, as to be more like the cabin of a steam-vessel, rather than any thing else I can compare them to.

In one of those I used in the tunnel I constructed at Brighton, above twenty people have sat with a table between them, covered with provisions, plates, dishes, &c. &c. which provisions were consumed according to the usual course of a dinner table: so that accommodations (even to that of a sofa for each person) which could not be thought of in coach or omnibus travelling, might be given to passengers.

Owing also to the size and construction of these carriages admitting of my using the air for springs, their motion would be soft and (as relates to the avoidance of all jolting) air-balloon-like, to a degree which you cannot conceive; and which no railway carriage, far less any common road vehicle, could compare with.

In point of safety, too, would they be incomparably superior; since, instead of being liable to break down, to be driven against any thing, to be run away with, or to be overturned, &c. &c. these accidents would be so impossible, that absolute immunity from danger, and certain security to life and limb, would be consequent on this method of conveyance; while the rate of transit under which this safety would be secured, being so great as to admit of the journey being effected in as few minutes as you thought proper, your route might be rendered as much shorter as you pleased in point of time, than the route by the Edgeware road could be rendered. The expense of the power too, by which your passengers would be conveyed, being above twenty times cheaper than coaches or omnibuses could convey them along the Edgeware Road, you would have a still greater advantage in this particular. It remains, therefore, only to point out how the public may be caused to take your circuitous line, in preference to the nearer route by the Edgeware Road.

In order to effect this, and to save the public from having to go from Hyde Park Corner to your line, as must be done were you to lay a railway down, I propose bringing your line to Hyde Park Corner, by extending the tunnel; branching it eastward from your basin, either through Kensington and Knightsbridge, under the turnpike road; or (in order to avoid all interference with, or opposition from, the Turnpike Commissioners) along the shorter line across the vacant grounds to the south of the road, at the back of Kensington and Knightsbridge; across (though beneath, and indeed underground all the way) Earl’s Court Lane, Gloucester Road, Grove Lane, the Brompton Road, and Sloane Street, to the vacant ground on the North and East of Wilton Crescent.

I am not, at present, prepared to point out either the best route, or the best spot for the termination towards Hyde Park Corner; having investigated only so for as to satisfy myself that such a course is practicable.

You will, at first, be startled at, and disposed to object to this extension, because you will suppose that it involves the outlay which would be required for two additional miles of tunnel, without bringing in any more return than would be received from passengers to the Birmingham Railway. This conception, however, is an erroneous one.

Were a method of conveyance in operation, by which the inhabitants of the west end of Kensington, of Earl’s Court, of North End, of Walham Green, of Brook Green, of Hammersmith, of Turnham Green, of Chiswick, &c. &c. could be carried (more safely than by coaches) from your basin to Hyde Park Corner in two or three minutes, instead of the twenty minutes or nearly half an hour which it now takes to get over that ground, they would so prefer your method of conveyance, as to render the additional outlay required for said two extra miles of tunnel, the most remunerating portion of your whole line; while, in addition to enabling you thus to convey passengers, said branch would enable you also to deliver coals, and other goods at Hyde Park Corner from your canal, for an expense of less than a penny per ton carriage from your canal thither; so that you would rival the Grosvenor Canal, and add importantly to the tonnage trade of your own canal by it.

Should the Birmingham and Bristol Railways be completed, this branch would also enable you to convey goods, as well as passengers, to and from them, and to and from the western parts of town, more cheaply than could any how else be done; an accommodation which laying down your railway could not give. And as I could so construct these two extra miles of tunnel, as to render their cost—the cost of the tunnel itself, i.e.—not more than about five thousand pounds per mile, the expense of this branch would not prove any ruinous addition to your contemplated outlay.

Therefore, for these reasons, I recommend you to prevent its being necessary that people should pay omnibus (or other) proprietors, to carry them from Hyde Park Corner to your basin at Kensington, in order that you may then convey them to the Birmingham (or Bristol) Railway, by extending your line towards Hyde Park Corner, in the manner I have pointed out.

Your case, brought into a focus, is as follows. You have expended a large sum in opening a line of conveyance which, owing to its not being carried far enough at first, does not combine all the advantages your situation admits of. You are, naturally, desirous that it should do this. If you open a communication for goods with the Grand Junction Canal, by extending your own canal, you will do this in degree. You have, therefore, for some years, contemplated carrying your canal up the height between your basin and the Grand Junction Canal. But the enormous expense of this has prevented you from doing it.

Being now informed that your object may be better effected by a railway, you entertain that idea; and as, were you to lay a railway down, passengers, as well as goods, might be conveyed by it, you are desirous of, if possible, bringing the “passenger trade,” between the Birmingham Railway and the west end of London, to your line.