ADDITIONAL NOTES (continued 2)

The several particular cases, concerning the collision of bodies, may be reduced to four general ones; viz.

1st. It may be, that one body only is in motion at the time of the stroke.

2nd. They may both move one and the same way.

3rd. They may move in direct opposition to each other, and that with equal quantities of motion.

4th. They may be carried with unequal motions in directions contrary to each other.

As the bodies may be either equal or unequal, each of these four general cases may be considered as consisting of two branches.

As to the first, if a body in motion strikes another equal body at rest, they will, according to the proposition, move together each of them with one half of the motion that the body had which was in motion before the stroke; and since the quantity of motion in any body is as the product arising from the multiplication of its quantity of matter into its velocity, the common velocity of the two bodies will be but one half of the velocity of the moving body before the stroke.

As to the second general case, where both the bodies are in motion before the stroke, and move one and the same way. In order to find their common velocity after impact, let the sum of their motions before the stroke be divided by the sum of the bodies, and the quotient will express the common velocity.

As to the third general case, where the bodies move in direct opposition to each other, if they have equal quantities of motion, they will upon the stroke lose all their motion, and continue at rest; for, by the proposition, the bodies after impact will be carried with the difference of their motions before the stroke; which difference, in such a case, is nothing.

When two bodies meet with unequal quantities of motion, if the difference of their motions be divided by the sum of the bodies, the quotient will express their common velocity after the stroke; for, by the proposition, the difference of their motions before the stroke is equal to the sum of their motions after the stroke; consequently, that difference divided by the sum of the bodies must give the velocity.

Such are the principal laws which govern the collision of bodies devoid of elasticity. The motions of elastic bodies are determined by different rules: for when they are perfectly elastic, the velocity gained by the body struck, and the velocity lost by the striking body, will be twice as great as if the bodies were perfectly inelastic. In estimating, therefore, the motions of such bodies, we may first consider what they would have been after impact, had they been inelastic, and thence deduce the desired conclusion. See Helsham’s Lectures, a work in which the subject appears to be very clearly treated.

Karn-brêh hill rises a little to the south-west of Redruth in Cornwall, to an elevation of 697 feet. Its principal interest is derived from the speculations of the antiquary, Doctor Borlase, who regarded it as having been once the grand centre of druidical worship; and he asserts, in his Antiquities of Cornwall, that, at this very time, the remains of those monuments which were peculiar to that priesthood may be discovered, such as rock-basins, circles, rock-idols, cromlechs, karns, caves, religious enclosures, logan stones, a gorseddau, or place of elevation, whence the druids pronounced their decrees, and the traces of a grove of oaks. This is all very ingenious and imposing, and may be easily believed by those who have either not visited the spot, or, having visited it, not viewed the objects with geological eyes. There is no ground whatever for considering the druidical monuments of Dr. Borlase as the works of man: on the contrary, they are evidently the results of the operation of time and the elements, the usual agents employed by Nature in the decomposition of mountain masses: but the age of antiquarian illusion is past; the light of geological science has dispelled the phantoms created by the wizard Fancy, just as the rising sun dissolves the mystic forms which the most common object assumes in twilight, when viewed through the medium of credulity and superstition. The “rock-basins” of antiquaries are rounded cavities on the surface of rocks, and are occasionally as spheroidal internally as if they had been actually formed by a turning-lathe. It was this artificial appearance which first suggested the hypothesis concerning their origin, and induced the antiquary to regard them as pools of lustration. It may, however, be remarked, in the first place, that, supposing them to have been the works of the druids, these priests must have been indefatigable artists, for there is scarcely a block of granite on which one or more of such pools are not visible, although some are, undoubtedly, much more complete and imposing than others. We shall introduce to the reader an account of these rock-basins in the words of their great defender, and we think that he will be amused with the ingenuity and confidence with which the antiquary dwells upon every appearance, and bends the facts to suit his favourite theory. “Since no author has mentioned, and attempted to explain these monuments, let us see what light and assistance their shape and structure, exposition, number, and place, considered together with the customs and known rites of antiquity, may afford us in this untrodden path. Of these basins there are two sorts; some have lips or channels to them, others have none; and therefore, as those lips are manifestly the works of design, not of accident, those that have so material a difference must needs have been intended for a different use, and yet both these sorts seem to be the works of the same people, for there is a multitude of these basins which have no lips or outlets, as well as those which have, to be seen on Karn-brêh hill, and elsewhere, on contiguous rocks. Their shape is not uniform; some are quite irregular, some oval, and some are exactly circular. Their openings do not converge in the top as a jar or hogshead, but rather spread and widen, as if to expose the hollow as much as possible to the skies. Some have little falls into a larger basin, which receives their tribute, and detains it, having no outlet. Other large ones intermixed with little ones have passages from one to another, and, by successive falls uniting, transmit what they receive into one common basin, which has a drain to it, that serves itself and all the basins above it.”

“The lips do not all point in the same direction, some tending to the south, some to the west, others to the north, and others again to the intermediate points of the compass; by which it seems as if the makers had been determined in this particular, not by any mystical veneration for one region of the heavens more than another, but by the shape and inclination of the rock, and for the most easy and convenient outlet.” We must here beg the reader to pause. The above remark is really too valuable to be suffered to pass without some notice. And so the absence of all design and arrangement is adduced as a proof of their artificial origin! What would Dr. Borlase have said, had all these lips been found to point in the same direction? But to proceed:

“The size of rock-basins is as different as their shape; they are formed from six feet to a few inches in diameter. Many uses may suggest themselves to the imaginations of the curious from the description of these new, and hitherto scarce-mentioned monuments; in order, therefore, to obviate some prepossessions, and prevent the mind from resting so far on groundless suppositions as may make it more difficult to embrace the truth, I shall first consider what, in all probability, cannot have been the design of them.”

The doctor then proceeds to show that they could never have been intended for evaporating salt; nor for pounding tin ore, nor for receiving obelisks, or stone deities, nor for altars; and then suggests that they could be no other than vessels most ingeniously contrived for holding holy-water for the rites of washing and purification. “If,” adds the learned antiquary, “fitness can decide the use--and where history is deficient, it is all reason that it should--we shall not long be at a loss. They are mostly placed above the reach of cattle, frequently above the inspection of man; nay, the stones which have these basins on them, do not touch the common ground, but stand on other stones.--Wherefore? but that the water might neither be really defiled by the former, nor incur the imaginary impurity, which touching the ground, according to the druid opinion, gave to every thing that was holy.” We do not know what ideas the druids entertained with respect to the purity of water, but we have seen water in some of these pools so impregnated with the excrement of sea-birds, that we must have been as thirsty as Tantalus, before we could have been induced to cool our tongues with it.

“But,” adds Dr. Borlase, “there are some basins which have no lip or channel; and, therefore, as they could not contribute any of their water to the common store, they must have been appropriated to another use; and since these are found in the same places with the others above-mentioned which have outlets or mouths to them, they must have been subservient to the same system of superstition, though in a different method.”

“These basins are sometimes found near twenty feet high from the common surface; and, therefore, being so withdrawn from vulgar eyes, so elevated from the ground, which was supposed, as I said before, to defile all, they had likely a proportionably greater degree of reverence, and their waters accounted more holy, and more efficacious.”

We shall not trouble the reader with any further quotations from this learned antiquary, except in concluding the history, after the fashion of melo-dramatists, with a splendid scene, in which, with the author’s assistance, we shall bring all the performers on the stage, dressed in appropriate costume, and surrounded by all the pomp of druidical worship.

“From these basins,” says Dr. Borlase, “on solemn occasions the officiating druid, standing on an eminence, sanctified the congregation with a more than ordinarily precious lustration before he expounded to them, or prayed for them, or gave forth his decisions. This water he drank, or purified his hands in, before it touched any other vessel, and was consequently accounted more sacred than the other holy-water. To these more private basins, during the time of libation, the priest might have recourse, and be at liberty to judge by the quantity, colour, motion, and other appearances in the water, of future events, of dubious cases, without danger of contradiction from the people below. This water might serve to mix their mistletoe withal, as a general antidote: for, doubtless, those who would not let it touch the ground, would not mix this their divinity (the mistletoe) with common water. Oak leaves, without which the druid rites did scarce ever proceed, ritually gathered and infused, might make some very medicinal or incantorial potion. Lastly, libations of water were never to be made to their gods, but when they consisted of this purest of all water, as what was immediately come from the heavens, and partly therefore thither to be returned, before it touched any other water or any other vessel whatsoever, placed on the ground.”

“As logan, or rocking-stones, were some of the piæ fraudes of the druids, the basins found on them might be used to promote the juggle; by the motion of the stone the water might be so agitated, as to delude the enquirer by a pretended miracle; might make the criminal confess; satisfy the credulous; bring forth the gold of the rich; and make the injured, rich as well as poor, acquiesce in what the druid thought proper.”

Sorry are we to destroy a web which has been so ingeniously woven by its author; but the interests of truth admit not of compromise. Dr. Macculloch, in an interesting paper, published in the Transactions of the Geological Society, on the decomposition of the granite tors of Cornwall, has justly observed, that the true nature of these rock-basins may be easily traced by inspecting the rocks themselves. On examination, they will always be found to contain distinct grains of quartz, and fragments of the other constituent parts of the granite. A small force is sufficient to detach from the sides of these cavities additional fragments, showing that a process of decomposition is still going on under favourable circumstances. The principal of these circumstances is the presence of water, or rather the alternate action of air and water. If a drop of water can only make an effectual lodgement on a surface of this granite, a small cavity is sure to be sooner or later produced; this will insensibly enlarge as it becomes capable of holding more water; and the sides, as they continue to waste, will necessarily retain an even and rounded cavity, on account of the uniform texture of the rock. This explanation is sufficiently satisfactory: in addition to which, it may be stated, that these very basins not unfrequently occur on the perpendicular sides of rocks, as may be distinctly seen in the granite of Scilly, and in the gritstone rocks in the park of the late Sir Joseph Banks, in the parish of Ashover, in Derbyshire; a fact which at once excludes the idea of their artificial origin.

The other grotesque and whimsical appearances of rocky masses, such as rock idols, logan stones, &c. are to be explained by the tendency which granite possesses of wearing more rapidly on the angles and edges than on the sides; thus, then, upon simple and philosophical principles, are such appearances to be satisfactorily accounted for, and the phantasmagoria of Borlase vanishes as the light penetrates the theatre so long dedicated to its exhibition.

We shall conclude this note with a few observations upon the celebrated logan, or logging, stone, near the Land’s End, Cornwall, of which we present our readers with a faithful sketch.

The foundation of this part of the coast is a stupendous group of granite rocks, which rise in pyramidal clusters to a great altitude, and overhang the sea. The celebrated logan stone here represented is an immense block weighing above sixty tons. The surface in contact with the under rock is of very small extent, and the whole mass is so nicely balanced, that, notwithstanding its magnitude, the strength of a single man applied to its under edge is sufficient to make it oscillate. It is the nature of granite to disintegrate into rhomboidal and tabular masses, which, by the further operation of air and moisture, gradually lose their solid angles, and approach the spheroidal form. The fact of the upper part of the cliff being more exposed to atmospheric agency than the parts beneath, will sufficiently explain why these rounded masses so frequently rest on blocks which still preserve the tabular form; and since such spheroidal blocks must obviously rest in that position in which their lesser axes are perpendicular to the horizon, it is equally evident that, whenever an adequate force is applied, they must vibrate on their point of support.

Although we are thus led to deny the druidical origin of this stone, for which so many zealous antiquaries have contended, still we by no means intend to deny that the druids employed it as an engine of superstition; it is possible that, having observed so curious a property, they dexterously contrived to make it answer the purposes of an ordeal, and, by regarding it as the touch-stone of truth, acquitted or condemned the accused by its motions. Mason poetically alludes to this supposed property in the following lines:--

“Behold yon huge

And unknown sphere of living adamant,

Which, poised by magic, rests its central weight

On yonder pointed rock; firm as it seems,

Such is its strange and virtuous property,

It moves obsequious to the gentlest touch

Of him whose heart is pure, but to a traitor,

Tho’ e’en a giant’s prowess nerved his arm,

It stands as fixed as Snowdon.”

We are indebted to Sir Everard Home for a description of that peculiar structure by which several species of animals are enabled to sustain their bodies in opposition to the force of gravity. His first paper upon this subject is published in the 106th volume of the Philosophical Transactions, in which he says, he was not aware that any animal, larger than the house-fly, was endowed by nature with such a power, so as to admit of examination, until Sir Joseph Banks mentioned that the lacerta gecko, a species of lizard, which is a native of the island of Java, comes out of an evening from the roofs of the houses, and walks down the smooth, hard, and polished chinam walls, in search of the flies which settle upon them, and which are its natural food, and then runs up again to the roof of the house. Sir Joseph, while at Batavia, amused himself with catching this animal, by standing close to the wall, at some distance from the lizard, with a long flattened pole, which being made suddenly to scrape the surface of the wall, knocked the animal down. He presented Sir Everard with a specimen weighing five ounces and three quarters, avoirdupois, which enabled him to ascertain the peculiar mechanism by which the feet of this animal can keep their hold of a smooth, hard, perpendicular wall, and carry up so large a weight as that of its body.

The foot has five toes, at the end of each of which, except that of the thumb, is a very sharp and much curved claw; on the under surface of each toe are sixteen transverse slits, leading to so many cavities or pockets, the depth of which is nearly equal to the length of the slit that forms the orifice; they all open forward, and the external edge of each opening is serrated, like the teeth of a small-toothed comb. The cavities, or pockets, are lined with a cuticle, and the serrated edges are also covered with it. The structure just described is supplied with various muscles, whose action is to draw down the claw, open the orifices of the pockets, and turn down the serrated edges upon the surface on which the animal stands. Upon examining attentively the under surface of the toes, when the pockets are closed, Sir Everard Home was struck with their resemblance to the surfaces of that portion of the Echineis remora, or sucking fish, by which it attaches itself to the shark, or to the bottom of ships; and it consequently suggested the probability of obtaining, from an examination of this latter apparatus, much useful information which might be applicable to the subject of the lizard, more especially as the parts of which it is composed are so much larger, and therefore more within the reach of anatomical examination.

The surface on the top of the head of this fish, fitted for adhesion, is of an oval form, and bears a considerable proportion to the size of the whole animal; it is surrounded by a broad, loose, movable edge, capable of applying itself closely to the surface on which it is placed; and it is evident that when the external edge is so applied, and the cartilaginous plates are raised up, the interstices must become so many vacua, and the serrated edge of each plate will keep a sufficient hold of the substance on which it rests to retain it in that position, assisted by the pressure of the surrounding water, without a continuance of muscular exertion. It thus appears that the adhesion of the sucking fish is produced by so many vacua being formed through an apparatus worked by the voluntary muscles of the animal, and the pressure of the surrounding water.

From the similarity of the mechanism of the under surface of the toes of the lacerta gecko, there can be no doubt that the purpose to which it is applied is the same: but as in the one case the adhesion is to take place under water, and is to continue for longer periods, the means are more simple; in the other, where the mechanism is to be employed in air, under greater disadvantages with respect to gravity, and is to last for very short periods, and then immediately afterwards to be renewed, a more delicate structure of parts, a greater proportional depth of cavities, and more complex muscular structure, become necessary.

Having ascertained the principle on which an animal of so large a size as the lacerta gecko is enabled to support itself in its progressive motion against gravity, Sir E. Home felt himself more competent to inquire into the mechanism by which the common fly is enabled, with so much facility, to support itself in still more disadvantageous situations. In the natural size the feet of the fly are so small, that nothing can be determined respecting them; Keller was the first person who made a drawing of the fly’s foot in a highly magnified state, in which the concave surfaces are visible, and which, no doubt, like those of the lizard above described, are employed to form vacua, which enable the fly to move under such disadvantageous circumstances. Mr. Bauer, who has so greatly distinguished himself in microscopic researches, was judiciously enlisted into the service of Sir E. Home upon this occasion; and he has shown that this principle, on which progressive motion against gravity depends, is very extensively employed by nature in the structure of the feet of insects; and Sir Everard observes, that, now this structure is known, it can be readily demonstrated by looking at the movement of the feet of any insect upon the inside of a glass tumbler, through a common magnifying glass; the different suckers are readily seen separately to be pulled off from the surface of the glass, and reapplied to another part.

In consequence of the expedition to the polar regions, Sir E. Home was enabled to obtain and examine the foot of the walrus, in which he detected a resemblance in structure to that of the fly; and it is not a little curious that two animals so different in size should have feet so similar in their use. In the fly the parts require to be magnified one hundred times to render the structure distinctly visible; and in the walrus the parts are so large, as to require being reduced four diameters, to bring them within the size of a quarto page.

Nor is progressive motion, the only function in which Nature avails herself of the pressure of the atmosphere for the accomplishment of her purposes. The act of feeding is continually effected in this manner. The operation of sucking is too familiar to require comment. It may not, perhaps, be so generally known, that it is by the very same process that bees reach the fine dust and juices of hollow flowers, like the honeysuckle, and some species of foxglove, which are too narrow to admit them. They fill up the mouth of the flower with their bodies, and suck out the air, or at least a large portion of it, by which the soft sides of the flower are made to collapse, and the juice and dust are squeezed towards the insect, as completely as if the hand had pressed it externally. It is by a similar process that the oyster is enabled to close its shell so firmly; for, if a hole be bored in it, it may be opened without the least difficulty.

Those who are not acquainted with the operations by which the mind is enabled to arrive at truth, are too apt to attribute to accident that which is the result of great intellectual labour and acuteness. Observation, analogy, and experiment are the three great stepping-stones by which the philosopher is enabled to ascend from darkness to light: it is true that his foot may accidentally be placed upon the first, but his own efforts are required to complete the ascent. To the mass of mankind the preliminary step is obvious, and they at once conclude that the succeeding ones are equally easy and simple. In this view of the subject, it was by accident that Sir Isaac Newton discovered the laws of gravitation, for his mind was directed to the investigation by the accidental fall of an apple from its tree; it was by accident that Galileo discovered the isochronous movement of the pendulum, for it was suggested by the vibration of a chandelier: but how many persons might have witnessed the fall of an apple, or the vibration of a chandelier, without arriving at similar truths? It has been said that we are indebted for the important invention in the steam-engine, termed hand gear, by which its valves or cocks are worked by the machine itself, to an idle boy of the name of Humphrey Potter, who, being employed to stop and open a valve, saw that he could save himself the trouble of attending and watching it, by fixing a plug upon a part of the machine which came to the place at the proper times, in consequence of the general movement. If this anecdote be true, what does it prove? That Humphrey Potter might be very idle, but that he was, at the same time, very ingenious. It was a contrivance, not the result of accident, but of acute observation and successful experiment. Glass is said to have been discovered by persons having accidentally kindled a fire on the sandy shore with sea-weed, when the alkali from the ashes united with the silex of the sand; and Pliny tells us that minium, or red lead, was first recognised, in consequence of a fire that took place at the Piræus at Athens, where some ceruse, which had been exposed to the fire, had been found converted into a red substance. A thousand such accidents might be related, were we not affording a sample rather than a catalogue. We are endeavouring to combat a popular but mischievous error; and we are happy at finding the same feeling expressed in a work which, from its extensive circulation, must prove highly useful in correcting it. “Very few discoveries,” says the author, “have been made by chance and by ignorant persons; much fewer than is generally supposed. They are generally made by persons of competent knowledge, and who are in search of them. The improvement of the steam-engine by Watt resulted from the most learned investigation of mathematical, mechanical, and chemical truths. Arkwright devoted many years, five at least, to his invention of spinning-jennies. The new process of refining sugar, by which more money has been made in a shorter time, and with less risk and trouble, than was perhaps ever gained by an invention, was discovered by Mr. Howard, a most accomplished chemist, and it was the fruit of a long course of experiments, in the progress of which, known philosophical principles were constantly applied, and one or two new principles ascertained.”--Library of Useful Knowledge.

If we include the pressure of the atmosphere, a body at the depth of 100 feet would sustain that of 60 pounds on the square inch; while one at 4,000 feet, a depth by no means considerable, it would be exposed to a pressure of about 1,830 pounds. We need not, therefore, feel surprised, that on the foundering of a ship at sea, though its timbers part, not a spar floats to the surface; for if the hull has sunk to a great depth, all that is porous is penetrated with water or greatly compressed. Captain Scoresby states that when, by the entangling of the line of the harpoon, a boat was carried down with the whale, it required after it was recovered two boats to keep it at the surface. Sir J. Herschel has recorded a melancholy anecdote, which may well be adduced in farther illustration of our subject:--“After the invention of the diving-bell, and its success in sub-aqueous processes, it was considered highly desirable to devise some means of remaining for any length of time under water, and rising at pleasure without any assistance. Some years ago an ingenious individual proposed a project by which this end was to be accomplished. It consisted in sinking the hull of a ship made quite water-tight, with the decks and sides strongly supported by shores, and the only entry secured by a stout trap-door, in such a manner, that by disengaging from within the weights employed to sink it, it might rise of itself to the surface. To render the trial more satisfactory, the projector himself made the first essay. It was agreed that he should sink in twenty fathoms water, and rise again without assistance at the expiration of twenty-four hours. Accordingly, making all secure, and provided with the means of making signals to indicate his situation, this unhappy victim of his own ingenuity entered and was sunk. No signal was made, and the time appointed elapsed. The pressure of the water at so great a depth had, no doubt, been completely under-estimated, and the sides of the vessel being at once crushed in, the unfortunate projector perished, before he could even make the signal concerted to indicate his distress.”

Hence pecunia from pecus. Opes quasi Oves. See Note 6.

If a soap-bubble be blown up, and set under a glass, so that the motion of the air may not affect it, as the water glides down the sides and the top grows thinner, several colours will successively appear at the top, and spread themselves from thence in rings down the sides of the bubble, till they vanish in the same order in which they appeared; at last a black spot appears at the top, and spreads till the bubble bursts. Hence it follows that the colours of a body depend in some degree upon the thickness and density of the particles that compose it; and that, if the density be changed, the colour will likewise be changed. That the production of colours depends upon the nature of the surfaces upon which light falls, is beautifully exemplified by the iridescence of mother of pearl; and which has been satisfactorily shown to depend upon a singular peculiarity in the structure of that substance. On its surface, which to the unassisted eye, and even to the touch, appears to be finely polished, there are innumerable little lines, or grooves, in some places as many as two or three thousand in the space of an inch, which, lying parallel, regularly follow each other in all their windings; by the edges of which the rays of light are reflected, and the continual change of colour arises from their continual bendings. Whatever doubts might have existed upon the subject, some late experiments of Dr. Brewster have dissipated them, by showing that the colours which play so beautifully on the surface of mother of pearl, may be communicated by pressure to sealing-wax and several other substances. The discovery of this fact was in some measure accidental; he had stuck a piece of mother of pearl on a cement made of rosin and bees-wax, and on separating this cement he found that it had acquired the property of exhibiting colours. Several persons who witnessed the effect, concluded that it arose from the presence of a thin film of the mother of pearl, which might have scaled off and adhered to the wax: but such an explanation was at once refuted, by plunging the wax in acid, which must have dissolved the mother of pearl, had any been present; but the acid had no effect, and the colours of the impression remained unimpaired. It is clear, then, that it is the grooves, as Dr. Brewster conjectured, which occasion the iridescence in the mother of pearl, as well as in the waxen impression. In consequence of this curious discovery, Mr. Barton succeeded in producing the same appearance on glass, and on different metals, by simply cutting grooved lines on their surface. These lines are so fine that, without a microscope, they are scarcely visible, and the glass and the metal appear to retain their polish: yet they and the colours also may be communicated by an impression, like those from the mother of pearl, to the wax. In like manner the varying and delicate hues exhibited by the wings of certain butterflies, arise from the action of light upon the parallel and equidistant striæ upon their surfaces.

The following are a few of those plants which indicate changes in the weather:--

Chickweed is an excellent barometer. When the flower expands fully, we are not to expect rain for several hours; should it continue in that state, no rain will disturb the summer’s day. When it half conceals its miniature flower, the day is generally showery; but, if it entirely shuts up, or veils the white flower with its green mantle, let the traveller take the hint and put on his great-coat. The different species of trefoil always contract their leaves at the approach of a storm; so certainly does this take place, that these plants have acquired the name of the husbandman’s barometer.

The tulip and several of the compound yellow flowers also close before rain. There is, besides, a species of wood-sorrel, which doubles its leaves before storms and tempests. The bauhinia, or mountain ebony, cassia, and sensitive plants, observe the same habit.

The popular adage of Forty days’ rain after St. Swithin, is a tradition which seems to have derived its origin from the following circumstance. Swithin, or Swithum, bishop of Winchester, who died in 868, desired that he might be buried in the open church-yard, and not in the chancel of the minster, as was usual with other bishops; and his request was complied with; but the monks, on his being canonized, considering it disgraceful for the saint to lie in a public cemetery, resolved to remove the body into the choir, which was to have been done with solemn procession on the 15th of July. It rained, however, so violently for forty days together at this season, that the design was abandoned. “Now, without entering into the case of the bishop,” says Mr. Howard, in his work on the Climate of London, “who was probably a man of sense, and wished to set the example of a more wholesome, as well as a more humble, mode of resigning the perishable clay to the destructive elements, I may observe, that the fact of the hindrance of the ceremony by the cause related is sufficiently authenticated by tradition; and the tradition is so far valuable, as it proves that the summers in this southern part of our island, were subject, a thousand years ago, to occasional heavy rains, in the same way as at present.” Mr. Howard has shown, by a table, that the notion commonly entertained on this subject, if put strictly to the test of experience, at any one station, in this part of the island, will be found fallacious; he, however, very justly observes, that “the opinion of the people on subjects connected with Natural History is commonly founded, in some degree, on fact or experience;” and to do justice to the popular observation in question, he states that, “in a majority of our summers, a showery period, which, with some latitude as to time and local circumstances, may be admitted to constitute daily rain for forty days, does come on about the time indicated by this tradition; not that any long space before is often so dry as to mark distinctly its commencement.”

Did the whale know his own power, he would easily destroy all the machinery which the art of man could devise for catching him; it would be only necessary for him to swim on the surface in a straight line in order to break the thickest rope; but the fish, on being struck by the harpoon, obeys a natural instinct, which, in this instance, betrays him to his death. Sir H. Davy, in his Salmonia, observes, that the whale, not having an air-bladder, can sink to the lowest depths of the ocean, and mistaking the harpoon for the teeth of a sword-fish, or a shark, he instantly descends, this being his manner of freeing himself from these enemies, who cannot bear the pressure of a deep ocean; and from ascending and descending in small space, he thus puts himself in the power of the whaler.--See Note 30.

boats impelled by paddling, rowing, &c.

To render the subject to which this note refers farther intelligible, we may show the means by which a fish moves forward in the water. The accompanying diagram and demonstration are from Dr. Roget’s Bridgewater Treatise.

The tail is the principal instrument by which the progressive motion is effected. Thus--suppose that the tail is inclined to the right; if, in this situation, the muscles of the left side, tending to bring the tail in a right line with the body, are suddenly thrown into action, the resistance of the water, by reacting against the broad surface of the tail in the direction P R, perpendicularly to that surface, will cause the muscular action to give the whole body an impulse in that direction; and the centre of gravity, C, will move onwards in the direction C B, parallel to P R. This impulse is not destroyed by the farther flexion of the tail towards the left side, because the principal force exerted by the muscles has already been expended in the motion from R to M, in bringing it to a straight line with the body; and the force which carries it on to L is much weaker, and therefore occasions a more feeble reaction. When the tail has arrived at the position L, indicated by the dotted outline, a similar action of the muscles on the right side will create a resistance and an impulse in the direction of K L, and a motion of the whole body in the same direction, C A. These impulses being repeated in quick succession, the fish moves forward in the diagonal C D, intermediate between the direction of the two forces.

Upon the same principle a boat is impelled by paddling; and the action of the rudder of a ship in turning the vessel will be readily understood. In this latter case, however, there is an additional mechanical advantage; since the point round which the vessel turns, is beyond the middle and towards the prow, and hence the force applied at the extremity of the keel acts as by an arm of a lever.

In appreciating the mechanical means by which a bird is enabled to direct its course, we must not omit to take into account the power it possesses of changing the position of the centre of gravity of its body, so that the reaction of the air may be modified with regard to each wing.

The command possessed by insects in directing and changing their course, seems more perfect even than that of birds. Many of them travel on their wings to immense distances, and, considering their comparative size, they generally move through the air with greater velocity than that of birds. Bees have been known to fly great distances from their hive, in search of food; and the silk-worm moth has travelled more than a hundred miles in a very short space of time. Many of our readers have, no doubt, noticed with surprise the apparent facility with which gnats have accompanied them, although they may have been advancing on horseback at a full gallop; and the author during the last summer has been forcibly struck with the manner in which flies and other insects have kept up with a railway carriage, alternately flying in and out of the vehicles, as though they had been at perfect rest. Some species possess a remarkable power of poising themselves in the air, and hovering for a length of time over the same spot, without falling or rising, advancing or retreating; the Dragon-fly affords a striking example of this fact.

In consequence of the manner in which the wings are affixed to the scapula, they give a stroke to the air in a direction both downwards and backwards; so that while the former supports the bird, the latter impels it forward. It is curious to notice that the degree of this obliquity varies in different birds, and is evidently adapted to their habits: thus, for instance, birds of prey have a great obliquity of wing, which better enables them to pursue their victims in a horizontal course; while those birds which soar to a considerable elevation, in a nearly vertical direction, as the Lark, have scarcely any obliquity of wing, but strike directly downwards.

This fact may be demonstrated by converting the triangle into a parallelogram, of which one of the sides of the triangle will become its diagonal: the other two sides will, of course, represent two forces equivalent to such diagonal, which, acting in opposition to it, must produce a balance.

The curious experiments of Mr. Faraday upon the optical effects produced by the revolutions of different wheels, might be exhibited by arrangements adjusted as messengers.

The sea and land breezes which occur in the islands of the torrid zone, very strikingly illustrate the position laid down in the text, and afford a good explanation of the manner in which winds may be occasioned by a change of temperature in the air. In these, during the hottest part of the day, the wind sets in from all quarters, and appears to be blowing towards the centre of the island, while in the night it changes its direction, and blows from the centre of the land towards the sea; for since the sun’s rays produce much more heat by their reflection from land than they do from water, that portion of air which is over the land will soon become heated, and will ascend; a rarefaction and diminution of the quantity of air over the central part of the land will be thus occasioned, which must be supplied from the sides; but, as the land cools again during the night, that portion of air which had been previously heaped up will begin to descend, and by spreading and equalizing itself will produce a breeze blowing from the centre.

The trade-winds, so called from the advantage which their certainty affords to trading vessels, are another example of the same kind; they are generally stated to blow from east to west over the equator, and are occasioned by the rarefaction of the air by the sun’s heat, and the motion of the earth from west to east. While writing the present note, we have seen an essay upon the subject by Captain Basil Hall, published in an appendix to Mr. Daniel’s admirable work on Meteorology: the perusal of this paper has induced us to cancel what we had written, and to refer the reader to the essay itself; for it is quite impossible to do justice to the views it entertains, in the limited space necessarily prescribed to us in this note.

On the coast of Guinea, the wind always sets in upon the land, blowing westerly instead of easterly; this exception arises from the deserts of Africa, which lie near the equator, and being a very sandy soil, reflect a great degree of heat into the air above them, which being thus rendered lighter than that which is over the sea, the wind continually rushes in upon the land to restore the equilibrium.

Among the irregular winds, or those which are not constant, but accidental, may be noticed the whirlwind, the harmattan, and the sirocco. The first of these is occasioned by the meeting of two or more currents of wind from opposite directions, and which can only be occasioned by some temporary but violent disturbance of equilibrium. The harmattan is met with on the western coast of Africa, and is generally attended by great heat and fog; it appears to be occasioned by a conflict between the heated sands of Africa, and the regular direction of the trade-winds over that continent, and, by disturbing their progress, it is frequently the forerunner of a hurricane in the West Indies. The sirocco occurs in Egypt, the Mediterranean, and in Greece, and is chiefly characterised by its unhealthy qualities. The air, by passing over the heated sands of Egypt, becomes so dried and rarefied as to be scarcely fit for respiration, and, being thus prepared, it absorbs so much humidity on passing the Mediterranean as to form a suffocating and oppressive kind of fog.

Mr. Daniel observes, that the currents of a heated room, in some measure, exemplify the great currents of the atmosphere. If the door be opened, the flame of a candle held to the upper part will show, by its inclination, a current flowing outwards; but, if held near the floor, it will be directed inwards. If the door be closed suddenly from without, it moves with the in-coming current, and against the out-going, and a condensation of air takes place in the room; which is proved by the rattling of the windows, and the bursting open of any door in the room, if slightly closed. If the door close from within, it moves against the in-coming current, and with the out-going, and a rarefaction of the air in the room takes place; which is evidenced by the rattling of the windows, and the bursting open of another door in the contrary direction.

Meteorology has been long considered the least perfect branch of natural knowledge; so apparently capricious and irregular are its phenomena, that philosophers had almost abandoned the idea of bringing them under the operation of any general laws. Brighter lights are, however, now dawning upon us. Mr. Whewell, in his Bridgewater Treatise, has explained the manner in which the various currents of the atmosphere maintain a necessary balance in the distribution of heat and moisture around the globe, and has thus reduced to order and design phenomena which have hitherto been regarded as unconnected and fortuitous. Lieut.-Col. Reid, by his late happy investigation of the law of storms, will, no doubt, lead us into a novel path of the most important discoveries. He has satisfactorily proved, by a mass of evidence derived from numerous logbooks, that storms obey fixed laws. His attention was ardently directed to the subject by having been at Barbadoes immediately after the great hurricane of 1831, which in the short space of seven hours killed upwards of 1400 persons on that island alone. The discoveries of Col. Reid may be thus briefly stated.--That hurricanes are whirlwinds of great diameter, always revolving according to an invariable law, viz. from right to left (supposing yourself standing in the centre), or in the opposite way to the hands of a watch, in the northern hemisphere, and in a contrary direction in southern latitudes; at the same time they have a progressive motion in a curved line, and as they advance their diameters appear to enlarge and their violence to diminish; it has been also found that in the centre of the vortex there is a lull, or calm. Col. Reid observes that the simplest mode of illustrating the subject is to cut out concentric circles, so as to represent progressive whirlwinds, by moving which over any tract, the veering of the wind will be easily understood. The reader may form a more familiar idea by causing the water to circulate in a basin, which will represent the violent circular motion of the storm-wind, with a calm in the centre of the vortex. Suppose this to be also moving onward at a rate of about seven miles an hour, and he will have a correct notion of the subject. Since the storms expand in size and diminish in force as they proceed towards the poles, and the meridians at the same time approach each other, gales become huddled together; and hence, apparently, the true cause of the very complicated nature of the winds in our latitude. Observations would also appear to render it probable that there exists an accordance of the force of storms with the law of magnetic intensity; for example, it is at its minimum at St. Helena, where storms never occur; on the contrary, the lines of greatest intensity seem to correspond with the latitudes of typhoons and hurricanes. To what important discoveries may not the pursuit of this enquiry lead us?

The practical importance of the foregoing facts must be obvious: to use the expression of Sir John Herschel, “they will teach seamen how to steer their ships, and save thousands of lives.” They will thus learn on which side to lay-to a ship in a storm, for, by watching the veering of the wind, they will ascertain the direction in which it is falling; if violent, and the changes sudden, the ship will probably be near the centre of the vortex; whereas, if the wind blows a great length of time from the same point, and the changes are gradual, it may reasonably be supposed the ship is near the extremity of it. The barometer also becomes a very important instrument upon these occasions; the rapid rotatory motion of a column of the atmosphere necessarily occasions its fall, and this fall is always greatest at the centre of the storm. When it begins to rise, the centre has passed, and when the wind has sufficiently abated to enable a ship to make sail, she may then bear away with safety; but near the middle of the hurricane, before the barometer begins to rise, all square-sails must be dangerous.

We are reminded, upon this occasion, of part of a stanza in the well-known ballad of Chevy Chace, where an English archer aimed his arrow at Sir Hugh Montgomery:--

“The grey goose wing that was thereon,

In his hearte’s blood was wett.”

The more ancient ballad, however, reads swane-feathers. In the “Geste of Robyn Hode,” among Mr. Garrick’s old plays, in the Museum, the arrows of the outlaw and his companions are particularly described:--

“With them they had an hundred bowes,

The strings were well ydight;

An hundred shefe of arrows good,

With hedes burnish’d full bryght;

And every arrowe an ell longe,

With peacocke well ydight,

And rocked they were with white silk,

It was a semely sight.”

And Chaucer, in the description of the squyer’s yeoman, says:--

“And he was clad in cote and hode of greene;

A sheafe of peacocke arrows bryght and shene,

Under his belt he bare full thriftely,

Well coude he dresse his tackle yemanly:

His arrowes drouped not with fethers lowe,

And in his hand he bare a mighty bowe.”

Prol. to Cant. Tales.

In order to show the dandyism displayed by the archers of former times, it may be stated, that, in the wardrobe accounts of the 28 Edw. I. p. 359, is a charge for verdigrise to stain the feathers of the arrows green. A wardrobe account of the 4 Edw. II. furnishes an entry for peacock arrows, “Pro duodecim flecchiis cum pennis de pavone, emptis pro rege de 12 den.”

As this note has some connexion with the shuttlecock,^[84] as well as the arrow, we may take this opportunity of introducing a passage, which was accidentally omitted in the text; it refers to the method of playing this game at Turon, in Cochin China; and which is described by a traveller as follows:--“Instead of using a battledoor,^[85] as is the custom in England, the players stood seven or eight in a circle; and after running a short race, and springing from the floor, they met the descending shuttlecock with the sole of the foot, and drove it up again with force high in the air. The game was kept up with much animation, and seldom did the players miss their stroke, or give it a wrong direction. The shuttlecock was made of a piece of dried skin rolled round, and bound with strings. Into this skin were inserted three feathers, spreading out at top, but so near to each other, where they were stuck into the skin, as to pass through the holes, little more than a quarter of an inch square, which were always made in the centre of Cochin copper coins. We made one or two awkward attempts at the game, not only to our own confusion, but much to the amusement of the natives. It must, however, be remembered, that, amongst these ingenious people, the feet assist, as auxiliaries to the hands, in the exercise of many trades, particularly that of boat-building.”

A beautiful experiment was lately instituted at Paris, to illustrate this fact, by Biot. At the extremity of a cylindrical tube, upwards of 3000 feet in length, a ring of metal was placed, of the same diameter as the aperture of the tube; and in the centre of this ring, in the mouth of the tube, was suspended a clock-bell and hammer. The hammer was made to strike the ring and the bell at the same instant, so that the sound of the ring would be transmitted to the remote end of the tube through the conducting power of the matter of the tube itself; while the sound of the bell would be transmitted through the medium of the air included within the tube. The ear being then placed at the remote end of the tube, the sound of the ring, transmitted by the metal of the tube, was first distinctly heard; and, after a short interval had elapsed, the sound of the bell, transmitted by the air in the tube, was heard. The result of several experiments was, that the metal of the tube conducted the sound with about ten and a half times the velocity with which it was conducted by the air; that is, at the rate of about 11,865 feet per second.

The biographer of Josquin des Prez, the celebrated musician, and maestro di capella to Louis XII. King of France, relates an anecdote which may be here told in connexion with the present subject. When Josquin was first admitted into the service of the French monarch, he had been promised a benefice by his Majesty; but this Prince, contrary to his usual habits, for he was in general both just and liberal, forgot the promise he had made; when Josquin, after suffering great inconvenience from the shortness of his Majesty’s memory, ventured by the following expedient to remind him publicly of his promise without giving offence. He had been commanded to compose a motet for the Chapel Royal, on which occasion he selected part of the 119th Psalm, “Memor esto verbi tui servo tuo”--“Oh think of thy servant, as concerning thy word,” which he set in so supplicating and exquisite a manner, that it was universally admired, particularly by the King, who was not only touched by the music, but felt the words so effectually, that he soon afterwards granted his petition, by conferring on him the promised preferment. For which act of justice and munificence, Josquin, with equal felicity, composed as a hymn of gratitude another part of the same Psalm,--“Bonitatem fecisti cum servo tuo, Domine”--“Oh Lord, thou has dealt graciously with thy servant.”

Josquin, among musicians, was the giant of his time, and seems to have arrived at universal monarchy and dominion over the affections and passions of the musical part of mankind; indeed, his compositions were as well known and as much practised throughout Europe at the beginning of the sixteenth century, as those of Handel were in Europe sixty years ago.

The following case, quoted by Sir David Brewster, in his work on “Natural Magic,” from the life of Peter Heaman, a Swede, who was executed for piracy and murder at Leith in 1822, will afford a very curious example of the influence of the imagination in creating distinct forms out of an irregularly shaded surface. “One remarkable thing was, one day as we mended a sail, it being a very thin one, after laying it upon deck in folds, I took the tar-brush and tarred it over in the places which I thought needed to be strengthened. But when we hoisted it up, I was astonished to see that the tar I had put upon it represented a gallows and a man under it without a head. The head was lying beside him. He was complete, body, thighs, legs, arms, and in every shape like a man. Now, I oftentimes made remarks upon it, and repeated them to the others. I always said to them all, ‘You may depend upon it that something will happen.’ I afterwards took down the sail on a calm day, and sewed a piece of canvass over the figure to cover it, for I could not bear to have it always before my eyes.”

The curious effect of chance resemblance was particularly remarked by Leonardo da Vinci in the moss and stains on old stones. And, in our own times, this faculty of the imagination has not unfrequently been enlisted into the service of the fortune-teller for purposes of fraud and imposition. The following story is related on credible testimony. “A British officer, in expectation of promotion, and of being united to a lady in marriage, sought a gipsy fortune-teller. The sorceress, no doubt, had made herself well acquainted with these circumstances. On entering the room, she ordered a large glass of spring-water, into which she poured the white of a newly-laid egg. After shaking the mixture for some time, she so far succeeded as to induce the credulous observer to declare that he saw most distinctly the image of the ship in which he was to hoist his flag, the church in which he was to be married, and his bride going with him into the church.”--The Gipsies’ Advocate, by J. Crabb.

Dr. Wollaston, in a paper published in the Philosophical Transactions, (1807, p. 133,) relates some interesting observations he made on the progressive changes of these rings, and which satisfactorily explain their origin. He observed, that some species of fungi were always to be found at the exterior margin of the dark ring of grass if examined at the proper season. The position of the fungi led him to believe, that progressive increase from a central point was the probable mode of formation of the ring; and he thought it likely that the soil which had once contributed to the support of fungi, might be so exhausted as to be rendered incapable of producing a second crop. The defect of nutriment on one side would occasion the new roots to extend themselves solely in the opposite direction, and would cause the circle of fungi continually to proceed, by annual enlargement, from the centre outwards. The luxuriance of the grass follows as a natural consequence, as the soil of an interior circle is enriched by the decayed roots of fungi of the succeeding year’s growth. During the growth of fungi, they so entirely absorb all nutriment from the soil beneath, that the herbage is often for a while destroyed, and a ring appears bare of grass, surrounding the dark ring; but, after the fungi have ceased to appear, the soil where they had grown becomes darker, and the grass soon vegetates again with peculiar vigour. Dr. Wollaston had many opportunities of remarking, that, when two circles interfere with each other’s progress, they do not cross each other, but are invariably obliterated between the points of contact. The exhaustion occasioned by each obstructs the progress of the other, and both are starved; a circumstance which affords a strong confirmation of the above theory.

In order to comprehend the nature of reciprocated vibration, or resonance, let the reader keep in his remembrance the analogy between musical vibration, and the oscillation of the pendulum, as explained at page 275. If he well understands the phenomena of the latter, he will readily comprehend those of the former. Galileo observed that a heavy pendulum might be put in motion by the least breath of the mouth, provided the blasts were often repeated, and made to keep time exactly with the vibrations of the pendulum: from the same sympathetic communication of vibrations will two pendulum clocks fixed to the same wall, or two watches lying upon the same table, take the same rate of going, though they would not agree with one another if placed in separate apartments. Mr. Ellicot indeed observed that the pendulum of one clock was even able to stop that of the other; and that the stopped pendulum, after a certain time, would resume its vibrations, and in its turn stop the vibrations of the other. We have here a correct explanation of the phenomena of Resonance; for the undulations excited by a vibratory body are themselves capable of putting in motion all bodies whose pulses are coincident with their own, and consequently with those of the primitive sounding body; hence the vibrations of a string, when another, tuned in unison with it, is made to vibrate.

Upon the same principle does the resonance, or reciprocated vibrations of columns of air, depend. We are much indebted to Mr. Wheatstone for our knowledge of this branch of acoustics; he has shown that, if a tuning-fork or a bell be sounded before a tube inclosing a column of air of the necessary length, the original sound will be augmented by the rich resonance of that air; and that the sounds of tuning-forks, if held before the cavity of the mouth, may be reciprocated most intensely by adjusting the alterable volume of air contained within it to the pitch of the instrument; by placing, for instance, the tongue, &c. in the position for the nasal continuous sound of ng (in song), and then altering the aperture of the lips, until the loudest sound was obtained, he readily accomplished his object.

If two vibrating tuning-forks, differing in pitch, be held over a closed tube, furnished with a moveable piston, either sound may be made to predominate, by so altering the piston as to obtain the exact column of air which will reciprocate the required sound. The same result may be obtained by selecting two bottles (which may be tuned with water) each corresponding to the sound of a different tuning fork; on bringing both tuning-forks to the mouth of each bottle alternately, that sound only will be heard, in each case, which is reciprocated by the unisonant bottle; or, in other words, by that bottle which contains a column of air susceptible of vibrating in unison with the fork.

Among the Javanese instruments brought to England by the late Sir Stamford Raffles, there is one called the gender, in which the resonances of columns of air are employed to augment, we might almost say to render audible, the sounds of vibrating metallic plates. Under each of these plates is placed an upright bamboo, containing a column of air of the proper length to reciprocate the lowest sound of such plate. If the aperture of the bamboo be covered with pasteboard, and its corresponding plate be struck, a number of acute sounds only (depending on the more numerous subdivisions of the plate) will be heard; but, on removing the pasteboard, an additional deep rich tone is produced by the resonance of the column of air within the tube.

It is only by a knowledge of this principle that the theory of the Guimbarde, or Jew’s harp, can be well understood.

The Memoires of Madame de Genlis first made known the astonishing powers of a poor German soldier on the Jew’s harp. This musician was in the service of Frederick the Great, and finding himself one night on duty under the windows of the king, played the Jew’s harp with so much skill, that Frederick, who was a great amateur of music, thought he heard a distinct orchestra. Surprised on learning that such an effect could be produced by a single man with two Jew’s harps, he ordered him into his presence; the soldier refused, alleging that he could only be relieved by his colonel; and that, if he obeyed, the king would punish him the next day for having failed to do his duty. Being presented the following morning to Frederick, he was heard with admiration, and received his discharge and fifty dollars. This artist, whose name Madame de Genlis does not mention, is called Koch; he has not any knowledge of music, but owes his success entirely to a natural taste. He has made his fortune by travelling about, and performing in public and private; and is now living retired at Vienna, at the advanced age of more than eighty years. He used two Jew’s harps at once, in the same manner as the peasants of the Tyrol; and produced, without doubt, the harmony of two notes struck at the same moment, which was considered by the musically-curious as somewhat extraordinary, when the limited powers of the instrument were remembered. It was Koch’s custom to require that all the lights should be extinguished, in order that the illusion produced by his playing might be increased.

It was reserved, however, for Mr. Eulenstein to acquire a musical reputation from the Jew’s harp. After ten years of close application and study, this young artist has attained a perfect mastery over this untractable instrument. In giving some account of the Jew’s harp, considered as a medium for musical sounds, we shall only present the result of his discoveries. This little instrument, taken singly, gives whatever grave sound you may wish to produce, as a third, a fifth, or an octave. If the grave tonic is not heard in the bass Jew’s harp, it must be attributed not to the defectiveness of the instrument, but to the player. In examining this result, you cannot help remarking the order and unity established by nature in harmonical bodies, which places music in the rank of exact sciences. The Jew’s harp has three different tones; the bass tones of the first octave bear some resemblance to those of the flute and clarionet; those of the middle and high to the vox humana of some organs; lastly, the harmonical sounds are exactly like those of the harmonica. It is conceived that this diversity of tones affords already a great variety in the execution, which is always looked upon as being feeble and trifling, on account of the smallness of the instrument. It was not thought possible to derive much pleasure from any attempt which could be made to conquer the difficulties of so limited an instrument; because, in the extent of these octaves, there were a number of spaces which could not be filled up by the talent of the player; besides, the most simple modulation became impossible. Mr. Eulenstein has remedied that inconvenience, by joining sixteen Jew’s harps, which he tunes by placing smaller or greater quantities of sealing-wax at the extremity of the tongue. Each harp then sounds one of the notes of the gamut, diatonic or chromatic; and the performer can fill all the intervals, and pass all the tones, by changing the harp. That these mutations may not interrupt the measure, one harp must always be kept in advance, in the same manner as a good reader advances the eye, not upon the word which he pronounces, but upon that which follows.

This project has lately been revived; in a late number of the Revue Encyclopédique there is a proposal to communicate verbal intelligence, in a few moments, to vast distances; and this not by symbols, as in the Telegraph, but in distinct articulate sounds uttered by the human voice. The plan is said to have originated with an Englishman, Mr. Dick, according to whose experiments the human voice may be made intelligible at the distance of twenty-five or thirty miles. It has been stated, in Note 44, that the celebrated Biot had ascertained that sound travels more than ten times quicker when transmitted by solid bodies, or through tubes, than when it passes through the open air; at the distance of more than half a mile the low voice of a man was distinctly heard. Father Kircher relates in some of his works, that the labourers employed in the subterranean aqueducts of Rome heard each other at the distance of several miles. The note which follows was published in the early edition of this work, before the subject attracted any notice, or any railroad had been completed. It is therefore reprinted without alteration.

It has often occurred to the author of these pages, during his reveries, that the means of conveying intelligence with immense rapidity may be hereafter invented by the Electrician.--Should a system of railways be established throughout the country, it might lead to some expedient by which such a desideratum could be accomplished through the medium of electrical discharges. Upon this subject we have accidentally fallen upon a curious notice in Arthur Young’s Travels in France (vol. i. p. 65). “M. Lomond has made a very curious discovery in electricity; you write two or three words on a paper, he takes it with him into his room, and there turns a machine inclosed in a cylindrical case, at the top of which is an electrometer of pith balls; by means of a wire, a connexion is made with a similar cylinder and electrometer in a distant apartment, and his wife, by remarking the corresponding motions of the balls, writes down the words they indicate; from which it appears that he has formed an Alphabet of Motion. As the length of the conducting wire makes no difference in the effect, a correspondence might be carried on at any distance, as, for example, within or without a besieged town; or for purposes much more interesting and useful. Whatever the uses may be, the invention is beautiful.”

The carrier is a variety of the common domestic pigeon, and which, from the superior attachment that it shows to its native place, is employed in many countries as the most expeditious courier. The letters are tied under its wing, it is let loose, and in a very short space returns to the home it was brought from, with its advices. This practice was much in vogue in the East; and at Scanderoon, till of late years, it was used on the arrival of a ship, to give the merchants at Aleppo a more expeditious notice than could be done by any other means. In our own country, these aerial messengers have been employed for a very singular purpose, having been let loose at Tyburn at the moment the fatal cart was drawn away, to notify to distant friends the departure of the unhappy criminal.

In the East, the use of these birds seems to have been greatly improved, by having, if we may use the expression, relays of them ready to spread intelligence to all parts of the country; thus it is stated by Ariosto (canto 15), that the governor of Damiata circulated the news of the death of Orrilo. “As soon as the commandant of Damiata heard that Orrilo was dead, he let loose a pigeon, under whose wing he had tied a letter. This fled to Cairo, from whence a second was despatched to another place, as is usual; so that, in a very few hours, all Egypt was acquainted with the death of Orrilo.”

But the simple use of them was known in very early times. Anacreon tells us (ode ix.) that he conveyed his billet-doux to Bathyllus by a dove.

Taurosthenes also, by means of a pigeon he had decked with purple, sent advice to his father, who lived in the isle of Ægina, of his victory in the olympic games, on the very day he had obtained it.^[86] And, at the siege of Modena, Hirtius without, and Brutus within the walls, kept, by the help of pigeons, a constant correspondence; baffling every stratagem of the besieger, Antony, to intercept their couriers. In the times of the crusades, there are many more instances of these birds of peace being employed in the service of war: Joinville relates one during the crusade of Saint Louis, and Tasso another, during the siege of Jerusalem.--Pennant’s British Zoology.

The Dutch variety is the most valuable; a pair of the best kind being worth from five to eight pounds. It is lighter than the English pigeon, and flies nearly as fast again. It proceeds at the rate of 60 miles an hour, and has been known to complete a journey of 800 miles, but this; it is presumed, is not continuous, but assisted by occasional rest. The bird learns but one lesson; it may carry from Antwerp to London, or to any other place, but it will only pass between two such places. It evidently travels by sight; when tossed, it circles, then rises in a spiral, observes its route and darts off. It will not fly at night; and, should the day be foggy, it is delayed, and sometimes lost.

The soothsayers attributed many mystic properties to the coral; and it was believed to be capable of giving protection against the influence of Evil Eyes: it was even supposed that coral would drive away devils and evil spirits; hence arose the custom of wearing amulets composed of it around the neck, and of making crowns of it. Pliny and Dioscorides are very loud in the praises of the medicinal properties of this substance; and Paracelsus says that it should be worn round the necks of infants, as an admirable preservative against fits, sorcery, charms, and even against poison. It is a curious circumstance that the same superstitious belief should exist among the negroes of the West Indies, who affirm that the colour of coral is always affected by the state of health of the wearer, it becoming paler in disease. In Sicily it is also commonly worn as an amulet by persons of all ranks; as a security against an evil eye, a small twisted piece, somewhat resembling a horn, is worn at the watch-chain, under the name of Buon Fortuna, and is occasionally pointed at those who are supposed to entertain evil intention. His late Sicilian Majesty was celebrated for his faith in, and frequent use of, the buon fortuna.--But to return to the coral usually suspended around the necks of children in our own country. In addition to the supposed virtues of the coral, it may be remarked that silver bells are usually attached to it, which are generally regarded as mere accompaniments to amuse the child by their jingle; but the fact is, that they have a different origin, having been designed to frighten away evil spirits. For the same superstitious objects were bells introduced into our churches as a species of charm against storms and thunder, and the assaults of Satan.

In farther illustration of the truth, that a custom has frequently survived the tradition of its origin, it may be here observed, that the common practice of persons who are unable to write, making their mark or cross, is derived from our Saxon ancestors, who affixed the sign of the cross, as a signature to a deed, whether they could write or not. Several charters still remain, to which kings and persons of great eminence affix “Signum Crucis manu propriá pro ignorantiá literarum.” Hence is derived the expression of signing instead of subscribing a paper. In like manner, the physician of the present day continues to prefix to his prescriptions the letter R, which is generally supposed to mean Recipe, but which, in truth, is a relict of the astrological symbol of Jupiter, formerly used as a species of superstitious invocation.

Alphesadi, an Arabian writer, quoted by Montucla in his Histoire des Mathematiques, expressly mentions the invention of chess as of Indian origin, and relates the following very curious Indian tradition:--Ardschir, King of the Persians, having invented the game of Tric-Trac, and being exceedingly vain of it, a certain Indian, named Sessa, the son of Daher, invented the game of chess, and presented his chess-board and chess-men to the king of the Indies. The sovereign was so much pleased, that he desired Sessa to name his reward, when this man made the apparently modest request, that he should receive as a gift so much corn as could be estimated by beginning with one grain, and doubling as many times as there were squares upon the chess-board, viz. 64. The king felt displeased at having his munificence thus slighted by a request so limited and so unworthy to be a gift from royalty; but, as Sessa remained firm, orders were given to the chief minister that he should be satisfied: when, however, the visir had by calculation ascertained the enormous quantity of corn which would be required, he waited upon the king, and with some difficulty convinced him of the fact; upon which the king sent for Sessa,--and said to him, that he admired his powers of calculation even more than the ingenuity of the game which he had presented to him, and, in respect to his promise as to the corn, he was compelled to acknowledge himself to be insolvent.

Dr. Wallis, the friend of Sir Isaac Newton, and Savilian Professor of Oxford, found that the quantity of corn would be such as to be capable of forming a pyramid, the measurement of which would be nine English miles in height, and nine similar miles for each of the four sides of the base. After this, Montucla also states some elaborate calculations made by himself, and proves, amongst other remarkable facts, that the quantity of corn in question would cover 162,000 square leagues to the depth of one foot, French measure, which would be at least three times the extent of the surface of France as it was about the year 1796, and which he estimates at 50,000 square leagues.

This problem is to be found in Hutton’s Recreations, and is stated as follows:--

“A person having in one hand an even number of shillings, and in the other an odd, to tell in which hand he has the even number.”

“Desire the person to multiply the number in the right hand by any even number whatever, and that in the left by any odd number; then bid him to add together the two products, and if the whole sum be odd, the even number of shillings will be in the right hand, and the odd number in the left; if the sum be even, the contrary will be the case. By a similar process, a person having in one hand a piece of gold, and in the other a piece of silver, we can tell in which hand he holds the gold, and in which the silver. For this purpose, some value represented by an even number, such as 8, must be assigned to the gold, and a value represented by an odd number, such as 3, must be assigned to the silver; after which the operation is exactly the same as in the preceding example.

“To conceal the artifice better, it will be sufficient to ask whether the sum of the two products can be halved without a remainder; for, in that case, the total will be even, and in the contrary case odd.

“It will be readily seen that the pieces, instead of being in the two hands of the same person, may be supposed to be in the hands of two persons, one of whom has the even number, or piece of gold, and the other the odd number, or piece of silver. The same operations may then be performed in regard to these two persons, as are performed in regard to the two hands of the same person, calling the one, privately, the right, and the other the left.”

It is by discovering the number of counters left on the board that this trick is performed. By means of a table the problem may be immediately solved; but as such a reference would be inconvenient, and, indeed, destructive to the magic of the trick, a Latin verse is substituted, which may be easily carried in the memory, and will be found to answer all the purposes of a table. In order, however, that the reader may become thoroughly acquainted with the machinery of the trick, we shall explain it in the words of its author. The problem is stated as follows: “Three things being privately distributed to three persons, to guess that which each has got.”

Let the three things be a ring, a shilling, and a glove. Call the ring A, the shilling E, and the glove I; and in your own mind distinguish the persons by calling them first, second, and third. Then take twenty-four counters, and give one of them to the first person, two to the second, and three to the third. Place the remaining eighteen on the table, and then retire, that the three persons may distribute among themselves the three things proposed without your observing them. When the distribution has been made, desire the person who has the ring to take from the remaining eighteen counters as many as he has already; the one who has the shilling to take twice as many as he has already, and the person who has the glove to take four times as many; according to the above supposition then, the first person has taken one, the second four, and the third twelve; consequently, one counter only remains on the table. When this is done, you may return, and, by the number left, can discover what thing each person has taken, by employing the following words:----

1 2 3 5 6 7

Salve certa animæ semita vita quies.

To make use of these words, you must recollect, that in all cases there can remain only 1, 2, 3, 5, 6, or 7 counters, and never 4. It must likewise be observed, that each syllable contains one of the vowels, which we have made to represent the things proposed, and that the first syllable of each word must be considered as representing the first person, and the second syllable the second. This being comprehended, if there remains only one counter, you must employ the first word, or rather the two first syllables, sal-ve, the first of which, that containing A, shows that the first person has the ring represented by A; and the second syllable, that containing E, shows that the second person has the shilling represented by E; from which you may easily conclude that the third person has the glove. If two counters should remain, you must take the second word cer-ta, the first syllable of which, containing E, will show that the first person has the shilling represented by E; and the second syllable, containing A, will indicate that the second person has the ring represented by A. In general, whatever number of counters remain, that word of the verse which is pointed out by the same number must be employed.

Instead of the above Latin verse, the following French one might be used:--

1 2 3 5 6 7

Par fer César jadis devint si grand prince.

In using the above line, it must be considered as consisting only of six words.

This problem might be proposed in a manner somewhat different, and might be applied to more than three persons. Those of our readers who may be desirous of further information on the subject, must consult Bachet in the 25th of his Problèmes plaisantes et délectables.

THE END.

Transcriber’s Notes

In order to get illustrations close to long descriptions and discussions of them, a few long paragraphs have been divided in two at logical places.

One obvious typographical error in punctuation was corrected.

All footnotes have been relocated at the ends of chapters.

Descriptive captions have been added by the transcribers for when the illustrations are not displayed, and are deemed by them to be in the public domain.