THE PRINTING PRESS By Otto L. Raabe

Throughout the stages of development of the book-printing press the chief object has been to lessen the cost of printing. Whether the direct purpose of an improvement has been to increase the working speed of the press, to lessen the necessary operating power, to simplify the mechanism, to strengthen the parts, to lighten the pressman's labor, or to better the quality of printing, the ultimate aim has always been the same. It has been the constant incentive to invention and the standard for judging the adaptability of a press.

The first printing press was the "wooden screw" press, which came into use about the middle of the fifteenth century, and was built upon the same mechanical principle as the linen presses in the homes of the well-to-do. This was the press used by Gutenberg.

It consisted of two upright timbers held together at the top and the bottom by crosspieces of wood and with two intermediate cross-timbers. One of these intermediate cross-timbers supported a wooden or stone "bed" on which the form of type was placed, and through the other passed a large wooden screw, the lower point of which was attached to the centre of a flat, wooden plate, called the "platen." The lower side of the platen was covered with a soft "packing" or "blanket" of cloth. After the type had been inked, a sheet of paper was laid on it. This paper had previously been dampened so that it would take a better impression of the type. The screw was then turned down until the platen pressed the paper against the inked type, and produced a printed sheet.

The form of type was incased in a frame called a "coffin." These coffins and the type within them were very heavy, but they had to be lifted in and out of the press by hand. After each impression the platen was screwed upward so that the sheet of paper which had been printed could be removed and hung up to dry.

This simple form of press continued in use without material change until the early part of the seventeenth century. The first improvements on it came about 1620, and consisted of a device for rolling in and out the wooden or stone bed on which the type rested instead of lifting it by hand, of a new form of iron hand-lever for turning the screw, and of an iron screw in place of the wooden one. These were the inventions of William Janson Blaeuw, a printer of Amsterdam. Blaeuw's press was introduced into England and used there as well as on the continent. It was substantially the same press as that on which Benjamin Franklin worked when in London in 1735.

After this first type of printing press had been in use for three and a half centuries, a much-improved form was invented by the Earl of Stanhope in 1798. The frame of his press was made of iron, cast in one piece; the bed, the impression plate, or "platen," and the other large parts were also of cast iron, while the working parts were of iron, steel, or brass. The iron impression screw was retained, but connected to it was a combination of levers whereby its power was greatly increased. This enabled the printing of larger forms and the use of a thinner and harder "packing," or "tympan," between the platen and the sheet of paper to be printed, resulting in a sharper and clearer impression. Much less exertion was required to work the lever, and at first, on this account, a printer, who was accustomed to use all his physical force on the old screw press, found it difficult to work on the new one.

This improved style of press was received with so much favor by printers that several persons took up its manufacture, and competition soon reduced its cost and brought it into general use for printing newspapers as well as books. The process of printing remained about the same as in the earlier presses. Two men were required to work it. One spread the ink on a wooden block, rolling over it with two leather-covered balls, about six inches in diameter, stuffed with wool or horsehair, and fastened to round wooden handles. Holding one of these inking balls in each hand, he then rolled one upon the other to distribute the ink evenly over both of them, and applied the ink to the face of the type by rocking the balls over it until the entire form was inked. While this was being done, the other man was placing the sheet of paper on the "tympan." This was a light frame, in two parts, really forming two frames, one inside the other, and both covered with parchment. There was a woollen or felt blanket between them, and the two frames were held together by hooks. The outer frame was hinged at its lower end to the outer end of the bed of the press, and when ready to receive the paper, it stood in a nearly upright position at about right angles to the bed. On the frame were two or four pins, upon which the sheet of paper was impaled.

Attached to the upper end of the inner frame by hinges was a thin and narrow frame, called the "frisket," of the same length and width as the inner tympan frame. This frisket was covered with strong paper in which were openings, cut a little larger than the size of the pages of the type-form. When the sheets of paper had been placed upon the tympan frame, the frisket was folded down upon it, and the two were then turned down over the form of type. The bed was then "run in" under the platen by means of a crank at the side of the press, and the platen was screwed down to make the impression. After the impression had been taken, the platen was screwed up, the bed "run out," the tympan frame and frisket lifted, and the printed sheet taken off.

The introduction of this Stanhope press gave a great impetus to the development of the printing press in other countries as well as in England, and many varieties were devised during the thirty years following. Although as early as 1811 Koenig had made a cylinder press which had proved fairly successful, the better grades of printing could be obtained only by the flat pressure of the hand-presses. In some of these hand presses, the platen, or upper impression plate, was moved into position over the bed and remained stationary while the bed with the type-form upon it was forced upward to make the impression. In others, the platen was hinged to the bed, but in all of them the mechanism was complicated.

The "Columbian" press, devised by George Clymer, of Philadelphia, in 1816, gained considerable distinction both in this country and in England, where it was introduced in 1818. It differed from the Stanhope in that the screw was dispensed with, the platen being depressed by a combination of levers and lifted by the aid of a weighted balance-lever.

The reduction of the hand-lever movement to its simplest and most powerful form is now seen in the Washington hand press, devised by Samuel Rust, of New York, in 1827. His patent was later purchased by R. Hoe & Co., who made nearly seven thousand of these presses in different sizes and still make many of a greatly strengthened pattern for taking fine proofs from photo-engraved plates. Some of these presses made before 1850 are still in use, and occasionally one hears of a Washington hand press being used for printing upon handmade paper an edition of a small and limited number of copies of a book. Of all the hand presses, this is the only one that has survived to the present day.

With the introduction of other means for applying power than the hand-lever, a distinction came to be drawn between printing presses and printing machines. The term "machine" might perhaps be more appropriately used for the huge printing presses of the present day, yet, as the first essential is the impression power, all other features being subordinate, the term "press" is still the proper one to apply, even to the greatest combination of printing units yet devised.

The "bed and platen" system of printing as first used in hand presses occupies such an important place in the history of the book-printing press that a further description of its career is necessary.

In December, 1806, Friedrich Koenig, a Saxon, who later gave to the world the first practical cylinder press, went from Germany to England to seek assistance in carrying out his plans for the construction of a greatly improved printing press, having failed in his efforts in his own country and in Russia. He succeeded in enlisting the support of Thomas Bensley, a London printer, and constructed a press in which all the operations but laying on and taking off of the sheet were performed mechanically.

An accurate description of this press is not extant, but it is known to have consisted of a large wooden frame, a platen worked by a vertical screw and gears, a type-bed drawn forward and backward by means of straps fastened to a large roller underneath the bed, a tympan frame and frisket arranged to open and close automatically with the movement of the bed, and an inking apparatus, consisting of an ink-box with a narrow slit in the bottom through which the ink was forced by a piston upon a roller below, from which it was transmitted by two intermediate rollers to another and lower roller which inked the form as it passed underneath. The two intermediate rollers had an alternating, lateral motion which spread or distributed the ink sideways before it reached the lowest roller.

This press was the first to have ink-distributing rollers and the first to be run by steam power. In April, 1811, the "Annual Register" for 1810 was printed on it by Mr. Bensley at the rate of eight hundred impressions an hour. Nothing further is recorded about this press, and it was probably abandoned as being too complicated.

In the following year, Koenig's first cylinder press was completed, to be followed two years later by an improved cylinder press made for the London Times, which will be referred to farther on.

In his experiments, the Earl of Stanhope had tried, without success, to find a substitute for inking-balls by making rollers covered with different kinds of skins. He also tried other materials, such as cloth, silk, etc., but the unavoidable seam and the impossibility of keeping these materials soft and pliable defeated his purpose. About 1813 inking-rollers made of a composition of glue and molasses came into general use, and this important invention was of great assistance in the further improvement of the printing press.

Other cylinder presses with mechanical inking appliances were devised and patented, the most notable of which were those of Rutt, Bacon, Cowper, Applegath, and Napier, but the mechanical imperfections of these presses unfitted them for the better grades of book printing.

Further efforts were, therefore, directed to increasing the output of the bed and platen presses by the application of improved inking devices, sheet-feeding, and impression mechanisms. About 1825 there was constructed by D. Napier, a machinist in London, a press containing such appliances which produced six to seven hundred impressions an hour. Other presses constructed upon the same principle, but with two type-beds, two sets of friskets, two inking mechanisms—and only one platen, in the centre of the press—were made by Hopkinson & Cope and by Napier, and were known as "double platen machines," though this is really a misnomer as there was only one platen.

Napier's invention achieved the greatest popularity and came into general use. At each end of his press there was an inking device, a type-bed, and a frisket, each set of which operated alternately with the other, but either could be made inoperative if the "feeder," or "layer-on," failed to place the sheet in time. Four boys, besides the printer, were required—two to lay on, and two to take off the sheets.

When the type-bed and the frisket carrying the sheet of paper were in position under the platen, the latter was drawn downward to make the impression by means of a "toggle" joint which acted upon two strong rods, one on each side, and was then raised again by a counterbalance weight. Owing to the awkward method of handling the paper, the working speed of the press was necessarily slow, and the size of the sheets limited to double royal, or 25 × 40 inches.

The best presses of this type were those devised and patented by Isaac Adams, of Boston, in 1830 and 1836, and by Otis Tufts, also of Boston, in 1834. R. Hoe & Co., of New York, acquired Adams' business in 1858 and continued the manufacture of his presses. Over one thousand in many different sizes were made by this firm, the largest printing a sheet 33 × 46 inches at a working speed of one thousand impressions an hour. The last Adams press was made in 1882, but quite a number are still in use in prominent printing-offices in New York, Boston, and a few other cities, where the results on fine book work are still considered better than from the faster cylinder presses. The mechanical principle employed in the Adams press for exerting a flat, parallel pressure has now been generally adopted for heavy stamping and embossing presses.

To go back to the early part of the nineteenth century, when Koenig found his bed and platen press impracticable, he immediately set to work, assisted by one of his countrymen, Andreas Bauer, a mechanic who had helped him formerly, and in the latter part of 1812, the first flat-bed cylinder press was erected by them in Bensley's office. The cylinder of this press had three impression surfaces with spaces between them, and each covered with a soft blanket. With each forward movement of the type-bed the cylinder made one-third of a revolution and then came to a standstill, while the bed returned to its starting-point. The spaces between the impression surfaces allowed the type-form to pass under the cylinder without touching the blankets. At the end of the cylinder and at equal distances along its circumference were hinged three frisket frames, each fitted with tapes having reel springs at one end. The frisket frame of the uppermost impression surface rested in a vertically inclined position against the high framework of the inking mechanism. The sheet of paper was placed upon the blanket, and the cylinder then turned forward, drawing the frisket frame down with it, while the tapes, kept taut by the reel springs, adjusted themselves to the curvature of the cylinder and held the sheet upon it. After one-third of a revolution, the cylinder came to a stop to let the type-bed return. On the next forward movement of the bed and the next one-third of a revolution of the cylinder, the impression was made, and on the next repetition of these movements, the sheet was taken off by hand, and the cylinder returned to its original position to have another sheet placed on the first frisket. At every complete revolution of the cylinder and three complete reciprocating movements of the bed, three sheets were printed.

The inking mechanism was similar to that employed on the bed and platen press, but the mechanism for forcing the ink through the slit in the bottom of the fountain was improved. The inking-rollers were covered with leather as before. The type-bed was moved by a very ingenious mechanism which is in use even at the present time, and is described farther on, when the two-revolution press is mentioned. The different parts were not connected with each other, the cylinder, the type-bed, the inking-rollers, and the fountain being operated independently by separate driving mechanisms. This press printed eight hundred sheets an hour, on one side. A part of Clarkson's "Life of William Penn" was printed on this press, and was the first book ever printed on a cylinder press.

Printers and publishers were sceptical as to the practical value of this novel invention, but Mr. John Walter, the proprietor of the London Times, with better foresight than the others, and needing increased facilities for printing his paper, contracted for two presses, each to have two impression cylinders. These were constructed for him with great secrecy in a building adjoining the pressroom of the Times, and on November 28, 1814, the entire edition of that paper was printed on them,—the first cylinder presses driven by steam power.

The mechanical principles were the same as in the first cylinder press. There were two impression cylinders, but only one type-bed, and the latter had, therefore, to travel a greater distance than in the single-cylinder press. This made it impossible to obtain quite double the output of the single-cylinder press, but each of these new presses produced eleven hundred impressions an hour, a very respectable performance for that early stage. The threefold motion of the cylinders was retained, but the frisket frames were displaced, and tapes running over rollers and underneath the cylinders held the sheets against the impression surfaces. An improvement was also made in the inking mechanism by the addition of an intermediate roller between the fountain and the upper distributing cylinder roller.

The next step in advance was the construction of the first of the so-called perfecting presses, which was patented, December 24, 1814, and erected in Mr. Bensley's office in 1815 or 1816. This press had two type-beds and two impression cylinders, one of each near either end of the press. The cylinders instead of having a threefold motion revolved continuously. The circumference of each corresponded approximately to the distance traversed by one of the beds. The part of the cylinder which made the impression was a little larger in diameter than the remainder, the low portion giving the necessary room for the type-bed to return without touching it. The board from which the sheets were "fed" was near the centre of the press, and at the top adjoining the feed board was an endless belt made of cloth as wide as the board and running with an intermittent motion over two rollers.

The sheet of paper was laid upon this belt, which then moved forward, carrying the sheet between the tapes and leading it to the top of, down and around, the first cylinder where it received the first impression. Thence the sheet was conveyed by the tapes to the top of and around the second impression cylinder and was printed on the reverse side, that is "perfected," and it was then taken from the lower side of the second cylinder by hand and laid upon a board in the centre of the press, between the two impression cylinders and underneath the feed board. This press printed both sides of a sheet 21 × 34-½ inches at a speed of nine hundred to one thousand an hour.

Shortly afterward a single-cylinder press was constructed upon the same principle, the forerunner of what is now known as the single large or drum cylinder press.

Within the next few years, Applegath and Cowper greatly simplified the presses in the Times and in Bensley's office by removing many of the gear wheels. They also invented the first inking-table, a flat, iron plate attached to the type-bed which enabled the rollers to distribute the ink more evenly than before. They placed rollers at an angle across the ink-table and introduced the revolving roller and the scraping blade in the ink-fountain.

More important, however, were Napier's inventions about 1824, of "grippers" which seized the sheet of paper at its front edge and drew it from the feed board, while the cylinder was in motion, and of a method of alternately depressing and raising the impression cylinders on the forward and backward stroke of the type-bed, making it unnecessary to have a part of the cylinders of smaller diameter than the rest to allow the type to pass under it as the bed returned. This made it possible to use cylinders of a smaller diameter. These improvements were first embodied in a perfecting press made for Hansard, a London printer.

Although a number of presses were already being operated by steam power, Hansard, in his description of the Napier bed and platen press (the "Nay-Peer," he called it) finds a peculiar advantage in that "it supersedes the necessity of steam power, as the motion of this machine is gained by two men turning a fly-wheel which acts as the impelling power."

I have described the development of the printing press up to this state with considerable detail, because it discloses the main principles of the book press of the present day. During the first quarter of the last century, the manufacture of cylinder presses was confined to England, not only because London was then the leading centre of civilization, but because nowhere else could be found the mechanical facilities for constructing the large metal frames and parts. Koenig left London for his native land in 1817, dejected by the treatment he had received at the hands of Bensley, both in financial matters and in the attempts to disparage his achievements. He was followed two years later by his friend Bauer, and together they founded the firm of Koenig & Bauer at Oberzell, where it still thrives as one of the largest factories in Germany.

It was not long, however, before the United States took the lead in the number of presses manufactured as well as in their improvement, and the present high state of efficiency of American presses makes them models which are copied in all other countries. These improvements and the perfections of details often presented problems which were more difficult to solve than those of the earlier inventors, and thousands of patents have been granted to Americans for new and ingenious devices.

The firm of R. Hoe & Co., which as early as 1822 was already engaged in the manufacture of hand-presses in New York, commenced about 1832 to manufacture flat-bed cylinder presses, beginning with the single large or drum cylinder press which was followed soon afterward by the single small cylinder and the double small cylinder press, the flat-bed perfecting press, the stop-cylinder press, the two-revolution press, and the rotary book press. They also made and are still making large newspaper and color presses which are used all over the civilized world, but of these we will not treat here.

As stated at the beginning of this article the chief object in press making has always been to lessen the cost of printing, but after increased speed had been attained, there came a demand for a press that would produce the finest quality of printing without sacrificing the quantity produced.

To meet this no press has ever surpassed the stop cylinder. It has been made in several different sizes, the largest having a type-bed 45 × 65 inches. Resting upon and attached to a heavy iron foundation are two iron side frames which are securely braced together by an upper iron frame, called the "rib." This upper frame contains four tracks faced with hard steel, on which run a series of friction rollers, supporting the iron type-bed. Attached to the front of the type-bed is an iron plate, called the ink-table, its surface level with the surface of the type-form as it lies upon the bed.

At the front of the press is the ink-fountain and a number of steel and composition rollers, called the "distributing rollers." The ink is delivered a little at a time from the fountain to the revolving distributing rollers, and from them to the ink-table which moves under the rollers with the motion of the type-bed. By this means the ink is distributed upon the entire surface of the ink-table in a thin, even film. From the ink-table the ink is taken by a set of six rollers, called the "form rollers." Resting on the form rollers and moving in contact with them are additional rollers which help to distribute the ink still finer before it reaches the type.

The impression cylinder is located at a distance from the front of the press of about two-thirds of the entire length of the press. The circumference of the cylinder is equal to the distance that the type-bed travels in one direction. When the type-bed moves from the front to the rear, the cylinder rotates in unison with it, and thus the cylinder makes one revolution. While the bed returns the cylinder does not move.

Near the rear of the press is a large wooden board extending across the press and lying in a slightly inclined position with its lower edge almost directly above the centre of the impression cylinder. This is the "feed board" upon which the sheets of paper lie before they are printed. The impression cylinder has a set of grippers, and when the cylinder is at rest, these grippers are close to the edge of the feed board and stand open to receive the edge of the sheet of paper. Extending a little over the front of the feed board are two gauges against which the front edge of the sheet of paper is placed, while one side edge of the sheet is placed against a gauge at the side of the feed board. Just an instant before the cylinder commences to rotate, the grippers seize the front edge of the sheet, and the gauges lift out of the way. The cylinder then carries the sheet around, meets the moving inked form, and makes the impression. Before the cylinder completes its revolution, the grippers open and release the sheet, and at the same instant another set of grippers on an adjoining cylinder, called the "delivery cylinder," seize the sheet. From this delivery cylinder the sheet runs down over a set of strings, and is lifted off the strings by a sort of fan, or "sheet flier," and deposited on a table at the rear of the press. This method of delivering the sheets is known as the cylinder or rear delivery. This press may also be fitted for "front delivery." By this method the sheet of paper after being printed is carried around on the impression cylinder until the front edge comes again to the feeding point. Just as the impression cylinder comes to a stop, a set of grippers seize the front edge of the printed sheet, draw it over and away from the impression cylinder, and deposit it, with the printed side up, upon a table near the front of the press and above the ink-fountain and distributing rollers.

The average speed of one of these presses is from one thousand to fifteen hundred impressions an hour, depending upon the desired quality of the work.

Notwithstanding the excellent qualities of the stop-cylinder press, commercial necessities often demand a sacrifice of quality to speed, and this has brought the two-revolution press into very general use. As the name implies, the cylinder makes two revolutions, one to print the sheet, and the other, an idle one, to allow the bed to return. While the bed is returning, the impression cylinder is lifted to clear the type-form. As the cylinder rotates continually at a uniform speed, the type-bed must also travel at a constant speed. The reversal of the movements of the bed must, therefore, take place in a short space of time.

The study of inventors has been concentrated upon this subject more than upon any other connected with flat-bed presses, and hundreds of patents for "bed motions" have been taken out. Considering the fact that in the larger presses the weight of the bed and form is about one and a half tons and that this weight moving at a speed of about six feet in a second must be brought to a full stop and put into motion again in the opposite direction at full speed in about one-quarter of a second, it is obvious that the problem was not an easy one, especially when the reversal of the bed must be accomplished without a jar or vibration. The mechanism employed has always been a driving gear and one or two toothed racks. In Koenig's original movement, the driving gear on the end of a rising and falling shaft ran on top of a rack attached to the bottom of the bed in order to drive the bed in one direction, and then descending around the end of the rack ran in the bottom to the same rack to drive the bed in the other direction and ascending at the other end to repeat the movement. This, as already stated, has proven a very efficient mechanism and is employed, with improvements, by some of the press manufacturers of the present time.

In a pamphlet entitled "A Short History of the Printing Press" (New York, 1902), by Robert Hoe, the writer describes a method of reversing the bed. Although somewhat technical, it seems desirable to quote him as follows: "As early as 1847, Hoe & Co. patented an entirely new bed-driving mechanism. To a hanger fixed on the lower side of the bed were attached two racks facing each other, but not in the same vertical plane, and separated by a distance equal to the diameter of the driving wheel, which was on a horizontal shaft and movable sideways so as to engage in either one or other of the racks. By this means, a uniform movement was obtained in each direction. The reversal of the bed was accomplished by a roller at either end of the bed entering a recess in a disc on the driving shaft, which in a half-revolution brought the bed to a stop and started it in the opposite direction. This involved a new principle; a crank action operating directly upon the bed from a shaft having a fixed centre, and within recent years modifications of this patent have been successfully employed to drive the type-bed at a high velocity and reverse it without a shock or vibration."

This invention appears to have been the forerunner of the more recent improvements in bed motions. A notable one is that employed in the Miehle presses, which have gained much celebrity, run at a high rate of speed, and are used in many printing-offices in this and other countries. The reversal of the bed movement is accomplished by a so-called "true crank" movement and with an absence of jar and vibration never before obtained in any other than the stop-cylinder presses.

At the present time, the latest development in printing presses is Hoe & Co.'s new two-revolution press, in which, also, the reversal of the bed is accomplished by the true crank movement, but with an improvement which brings it to an easy stop and returns it without the least vibration.

On all two-revolution presses there are employed, to assist in the reversal of the bed, air-chambers or cylinders, without which the reversing mechanisms could not withstand the enormous strain to which they are subjected. These are iron cylinders, closed at one end, approximately six inches in diameter and eighteen inches long, and varying in size according to the size of the press. Some presses have two and others four of these cylinders, one or two at each end. The open ends of the cylinders are toward the bed, and attached to the bed are two or four pistons which enter the air-chambers as the bed nears the end of its stroke. The compression of the air in the cylinders makes a cushion and checks the momentum of the moving bed. The pistons can be adjusted to regulate the air compression to suit the velocity of the bed and the weight of the form, which vary in different kinds of work.

The delivery of the printed sheets is performed either by a delivery cylinder or by a front delivery with the printed side of the paper uppermost as already described for the stop-cylinder presses. Grippers are not used in the front delivery carriage, as the sheet is discharged from the cylinder by its continuous rotation.

The average running speed of a two-revolution press is about one-third greater than that of a stop cylinder, or about eighteen hundred impressions an hour, as against from one thousand to thirteen hundred and fifty impressions from the stop cylinder, this being the comparison in presses of the average size, printing sheets about 33 × 46 inches. The driving power required is in the proportion of about five for the two-revolution press to three for the stop cylinder, and the wear and tear is in about the same proportion.

Another press, which is still employed to a small extent for book-work, is the flat-bed perfecting press. This press is virtually two two-revolution presses combined into one, with the advantage that they require only one man as "feeder," but with the disadvantage that they produce only about two-thirds as much work as two separate single-cylinder, two-revolution presses. Their greatest disadvantage lies in the difficulty of preventing the fresh ink on the side of the sheet first printed from "setting off" on the packing of the cylinder which prints the reverse or second side. Mechanisms are employed to move the "tympan sheet" or outside covering of the second cylinder along at fixed intervals, but they are complicated and troublesome. These presses are expensive and cumbersome, and can generally be used only for inferior grades of work in large editions. Under the care of a skilful and painstaking pressman, good work can be produced from them, but fine book-work is always done on stop-cylinder and two-revolution, single-cylinder presses, which have now been brought to a high state of perfection.

Nearly a hundred years ago Hansard wrote, "The printing machine in its present state appears susceptible of little improvement." He was, in truth, right so far as the main principles of the flat-bed cylinder press are concerned, but there have been immense improvements in many of the details. With the introduction of automatic sheet-feeding devices, and improvements in the driving, inking, and delivery arrangements, mechanical ingenuity seems to have been exhausted. The temptation is strong to apply Hansard's prediction to the flat-bed cylinder press of the present day, but with the many surprises that meet us in other fields this would border on temerity.

Already there have been great advances in adapting the entirely rotary principle to the printing of high-grade work, although its use is still restricted to the production of large editions.

As early as 1852 Hoe & Co. made a rotary press for D. Appleton & Co., especially for printing the famous Webster spelling-book. The types were locked up on the cylinders in curved beds, called "turtles," and the sheets were delivered by a sheet-flier. Probably thirty million copies were printed on this press, which was dismantled nearly twenty-six years ago.

In 1886 this same concern made a press which is still used for printing some of the forms of the Century Magazine. This press had two pairs of cylinders, and curved electrotype plates were used on it. The paper was in a roll at one end, and at the other end there were delivered, to each revolution of the cylinders, eight eight-page signatures already folded to the size of the Century page. This was the first rotary press made for a good grade of book-work. Two similar presses were afterward made for Harper's Weekly and for the Strand Magazine of London.

What is known as the rotary art press was made in 1890 for printing the fine half-tone illustrations in the Century Magazine.

This has one plate cylinder and one impression cylinder, and curved electrotype plates are used. The sheets are "fed" by hand in the usual manner, and are printed on one side at a time and delivered by a sheet-flier. It produces as much work as four flat-bed cylinder presses and of better quality. The plates are inked by sixteen rollers. The performance of this press is another demonstration of the superiority of the rotary over the flat-bed principle of printing.

Since then hundreds of rotary presses have been made for magazine and book printing, most of them equipped with attachments for folding the sheets as they are printed, and all having a high rate of speed. C. B. Cottrell & Co. have made many rotary presses for magazine printing, most of which deliver the sheets flat, without folding, and most of them made to suit some predetermined size or sizes of sheets or pages.

In the evolution of the printing press there are three sharply defined stages: first, the flat impression surface and the flat printing surface, requiring the exertion of all of the impressing power upon the entire surfaces; second, the cylindrical impression surface and the flat printing surface, requiring the exertion of all of the impressing power upon only a narrow line or a small portion of the printing surface; third, a cylindrical impression surface and a cylindrical printing surface, still further reducing the area upon which all the impressing power is exerted.

Just as the second stage has, particularly for book-work, virtually superseded the first, so the third is destined to supersede the second. It is only an adaptation of the means to the ends. The mechanical principles of the rotary press are, in fact, simpler than those of the flat-bed cylinder press, and it may be said that so far as the purely mechanical part of the press is concerned, they have been fully developed, but much still remains to be done in other directions. The variety in the sizes of the pages of different books, the smallness of the editions, and the fact that the finer grades of paper, especially coated paper, cannot be obtained in roll form, are obstacles to be removed. As most book forms are electrotyped for flat-bed presses, and as it requires but little additional expense to curve the plates, this one item is not much of an obstacle to overcome. It is, however, still difficult to curve the plates perfectly, and the pressmen, even if they can produce excellent work from flat-bed presses, require considerable training if they have had no experience on rotary presses. All these difficulties are sure to be overcome in time.[Back to Contents]