PRINTING MACHINE

Having, on the first trial of their machines, discovered the superiority of the inking roller and table over the common balls, they immediately applied them to the common press, and with complete success. The invention, however, was immediately infringed throughout the kingdom, and copied in France, Germany, and America; and it would have been as fruitless to attempt to stop the infringement of the patent as it was found in the case of the kaleidoscope. This invention has raised the quality of printing generally.

above them. As the inking table attached to the revolving drum passes each of these ductor rollers, it receives from them a coating of ink. It next encounters the inking rollers, to which it delivers this coating. The types next, by the continued revolution of the drum, encounter these inking rollers, and receive from them a coating of ink, after which they meet the paper cylinders, upon which they are impressed, and the printing is completed.'

Thus in a single revolution of the great central drum the inking table receives a supply eight times successively from the ductor rollers, and delivers over that supply eight times successively to the inking rollers, which, in their turn, deliver it eight times successively to the faces of the type, from which it is conveyed finally to the eight sheets of paper held upon the eight cylinders by the tapes.

Let us now explain how the eight cylinders are supplied with paper. Over each of them is erected a sloping desk, upon which a stock of unprinted paper is deposited. Beside this desk stands the layer on, who pushes forward the paper, sheet by sheet, towards the fingers of the machine.

Improvements in printing machines were effected by Mr. Wayte and by Mr. David Napier; but the immense and increasing demand of the Times upon their powers, rendered it necessary to provide a machine which would work off from 12,000 to 15,000 copies per hour. This demand was supplied by the invention of the late Mr. Applegath, who gave the author the following description, first published by the late Dr. Lardner: He decided on abandoning the reciprocating motion of the type form, arranging the apparatus so as to render the motion continuous. This necessarily involved dizelar motion, and accordingly he resolved upon attaching the columns of type to the sides These fingers, seizing upon it, first draw it of a large drum or cylinder, placed with its down in a vertical direction between tapes in axis vertical, instead of the horizontal frame the eight vertical frames until its vertical edges which had been hitherto used. A large central correspond with the position of the form of type drum is erected, capable of being turned round on the printing cylinder. Arrived at this posiits axis. Upon the sides of this drum are tion, its vertical motion is stopped by a selfplaced vertically the columns of type. These acting apparatus provided in the machine, and columns, strictly speaking, form the sides of it begins to move horizontally, and is thus a polygon, the centre of which coincides with carried towards the printing cylinder by the the axis of the drum, but the breadth of the tapes. As it passes round this cylinder it is columns is so small compared with the diameter impressed upon the type, and printed. It is of the drum, that their surfaces depart very then carried back horizontally by similar tapes little from the regular cylindrical form. On on the other side of the frame, until it arrives another part of this drum is fixed the inking at another desk, where the taker off awaits table. The circumference of this drum in the it. The fingers of the machine are there disTunes printing machine measures 200 inches, engaged from it, and the taker off receives and it is consequently 64 inches in diameter. it, and disposes it upon the desk. This moveThis drum is surrounded by eight cylinders, ment goes on without interruption; the moalso placed with their axes vertical, upon which ment that one sheet descends from the hands the paper is carried by tapes in the usual man- of the layer on, and being carried vertically per. Each of these cylinders is connected with downwards begins to move horizontally, space the drum by toothed wheels, in such a manner is left for another, which he immediately supthat their surfaces respectively must necessarily plies, and in this manner he delivers to the move at exactly the same velocity as the sur-machine at the average rate of two sheets every face of the drum. And if we imagine the drum five seconds; and the same delivery taking place thus in contact with these eight cylinders to be put in motion, and to make a complete revoluton, the type form will be pressed successively against each of the eight cylinders, and if the type were previously inked and each of the fight cylinders supplied with paper, eight sheets of paper would be printed in one revolution of the drum.

It remains, therefore, to explain, first, how the type is eight times inked in each revolution; and secondly, how each of the eight cylinders is supplied with paper to receive their impression. Beside the eight paper cylinders are placed eight sets of inking rollers; near these are placed two ductor rollers. These ductor rollers ceive a coating of ink from reservoirs placed

at each of the eight cylinders, 16 sheets are delivered and printed every five seconds. It is found that by this machine in ordinary work between 10,000 and 11,000 per hour can be printed; but with very expert men to deliver the sheets, a still greater speed can be attained. Indeed, the velocity is limited, not by any conditions affecting the machine, but by the power of the men to deliver the sheets to it.

In case of any misdelivery a sheet is spoiled, and, consequently, the effective performance of the machine is impaired. If, however, a still greater speed of printing were required, a machine of the same kind, without changing its principle, would be sufficient for the exigency;

PRINTING MACHINE

but it would be necessary that the types should be surrounded with a greater number of printing cylinders.

It may be right to remark, that these surrounding cylinders and rollers, in the case of the Times machine, are not uniformly distributed round the great central drum; they are so arranged as to leave on one side of that drum an open space equal to the width of the type form. This is necessary in order to give access to the type form so as to adjust it.

One of the practical difficulties which Mr. Applegath had to encounter in the solution of the problem, which he has so successfully effected, arose from the shock produced to the machinery by reversing the motion of the horizontal frame, which in the old machine carried the type form and inking table, a moving mass which weighed one ton! This frame had a motion of 88 inches in each direction, and it was found that such a weight could not be driven through such a space with safety at a greater rate than about 45 strokes per minute, which limited its maximum producing power to 5,000 sheets per hour.

Another difficulty in the construction of this vast piece of machinery was so to regulate the self-acting mechanism that the impression of the type form should always be made in the centre of the page, and so that the space upon | the paper occupied by the printed matter on one side may coincide exactly with that occupied by the printed matter on the other side. The type form fixed on the central drum moves at the rate of 70 inches per second, and the paper is moved in contact with it of course at exactly the same rate. Now, if by any error in the delivery or motion of a sheet of paper it arrive at the printing cylinder 1-70th part of a second too soon or too late, the relative position of the columns will vary by 1-70th part of 70 inches-that is to say, by one inch. In that case the edge of the printed matter on one side would be an inch nearer to the edge of the paper than on the other side. This is an incident which rarely happens, but, when it does, a sheet is, of course, spoiled. The waste, however, from that cause is considerably less in the present vertical machine than in the former less powerful horizontal one.

cessary that something more should be done. An American machine, the invention of Messrs. Hoe and Co. of New York, has been recently introduced into this country, and several have been constructed by Mr. Whitworth of Manchester for the Times and other newspapers. By means of these machines, combined with a recently discovered process of stereotyping and multiplying type-high forms, there is practically no limit to the number of copies of a newspaper which can be produced within a given time.

The printing presses of Messrs. Hoe and Co. had, like Applegath's vertical machines, been invented previous to 1851, and cannot therefore be regarded as novelties; but at that date only one had been introduced into Europe, and no sample or even model was exhibited in Hyde Park. There was a small model of the ten-cylinder press in the Exhibition of 1862, but nothing else to illustrate the mechanism by which the principal newspapers of the metropolis and great provincial towns are printed. The first presses sent by Messrs. Hoe and Co. to this country were for Lloyd's Weekly Newspaper, and were of the six-cylinder size. These were followed by two ten-cylinder machines ordered by Mr. Walter for the Times, with the condition that they were to be made by an English machinist who should be approved by him. The Star and the Manchester Examiner also ordered Hoe presses of English make, and the example thus set was speedily followed by the Manchester Guardian, the Daily Telegraph, the Scotsman, the Illustrated London News, and in fact all the leading papers in the United Kingdom. The experience, however, of the English-made machines, had meanwhile (probably from the novelty of the manufacture) not been quite so satisfactory as that of those produced by Messrs. Hoe and Co., and this gave a decided preference to the New York machines. Mr. Walter still continues to use two of Applegath's eight-cylinder vertical machines in printing the Times and Evening Mail, but only as subsidiaries, the chief burden of the work falling on the two ten-cylinder Hoes made by Mr. Whitworth, and these are now said to perform admirably. They are driven at the rate of thirty-two revolutions per minute, which gives a printing rate of 19,200 per hour,

The vertical position of the inking rollers is more conducive to the goodness of the work-or about 16,000 including stoppages. Much of for the type and engraving are only touched on their extreme surface-than the horizontal machine, where the inking rollers act by gravity; while any dust shaken out of the paper, which formerly was deposited upon the inking rollers, now falls upon the floor. With this machine 50,000 impressions have been taken without stopping to brush the form or table.

the ingenuity exercised both in the Applegath and Hoe machines was directed to the chase, which had to hold securely upon its curved face the mass of movable type required to form a page. The complicated contrivances by which this was effected have now been entirely superseded by the use of stereotype plates; but before proceeding to describe the The principle of this vertical cylinder ma- process by which these are obtained, it may be chine is capable of almost unlimited extension. well to draw attention to some of the points Notwithstanding the great powers of pro- which seem to have determined the preference duction of Mr. Applegath's machine, the still- now given to the Hoe presses over the Appleincreasing requirements of the Times, with the gath. The course of the sheet in laying on repeal of the paper duty and the consequent at the Hoe machine is as direct as it can be demands of the cheap newspapers, made it ne-made, short of printing from a continuous web,

PRINTING, NATURE

PRISMATIC COMPASS

tuns of 252 gallons each. This low price of wine was partly due to the fact that French wine was freely consumed in England six hundred years ago, partly to the political connection which subsisted between this country and Guienne up to the latter part of the fourteenth century. After the rupture of the peace of Bretigny, and the reduction of Guienne, French wine became much dearer. [WINE.]

and the taking off is performed with great re-purchased, and frequently did purchase, two gularity by means of a wooden frame, which rises and falls with each impression of the printing cylinders. At the Applegath press the direction of the sheet has to be changed from a perpendicular to a lateral motion to correspond with the vertical position of the main drum. A taker off is also required for each impression cylinder as well as a layer on, thus considerably increasing the number of hands. The American machine also possesses Priscillianists. In Ecclesiastical History, a decided superiority in the arrangements for a sect of the fourth century; so named from securing good register, though the ingenious Priscillian, a Spanish bishop, put to death in A.D. finger motion by which this result is obtained 382 by Maximus, tyrant of Gaul, on the accusabecomes objectionably rapid in the largest size tion of another bishop, Ithacius; the earliest inof presses. For the mode of producing the stance of anyone put to death for heresy. The plates for the Times and other newspapers, see opinions of Priscillian and his followers are STEREOTYPING. I said to have been Manichæan; but it is remarkable that Sulp. Severus, himself sufficiently zealous against their doctrines, admits that their persecutor Ithacius was a man of disreputable character, and that purity and austerity of manners were often sufficient with him to ground an accusation of Priscillianism. This affords a curious parallel with the history of the twelfth and thirteenth centuries, when accusations of Manicheism were liberally brought against sectaries whose avowed tenets extended only to the reformation of ecclesiastical matters and denial of the church's authority. (Milman's Latin Christianity, bk. ii. ch. iv.)

The Spottiswoode Press. The first successful application of steam, as a motive power, to printing presses with a platen and vertical pressure, was made in the establishment where this Dictionary is printed. Convinced of the superiority of the impression made by flat as compared with that of cylindrical pressure, the late Mr. Andrew Spottiswoode (a name to be remembered amongst the most eminent in his profession), assisted by his chief engineer, Mr. Brown, succeeded, after many experiments, in perfecting a machine which combines the excellence of work of the hand press with four times its speed, and with a uniformity of colour which can never be attained by inking by hand. The main point of the invention is the endless screw or drum which takes the carriage and type from each end under the platen, and after the impression is taken by means of a crank returns it to its original position. The frisket is attached to the tympan at the bottom near the tympan joints, so that when the tympan is lifted from the form by the machinery, the tympan and frisket open at the upper end, contrary to the usual way in presses worked by manual labour, and the printed sheet is left on the tympan resting on the frisket. These presses are called double platens; but they ought, in honour of their inventor, to be named Spottiswoode presses.

Printing, Nature. [NATURE PRINTING.]
Prior. [ABBOT.]

Prioress. The superior of certain convents of nuns.

Prisage (Fr. prise, a taking). An ancient right of the crown, by which the king or his butler was empowered to take two tuns of wine from every ship importing twenty tuns or more into England. It is mentioned in the earliest pipe rolls as a source of royal revenue. By a charter of Edward I. it was commuted to a tax of two shillings on every tun of wine imported by merchant strangers. The commutation, on the presumption that thirty to forty tuns were the average lading of a ship carrying Bordeaux or Gascony wine, is pretty nearly equivalent to the ordinary price of wine at the latter end of the thirteenth century, i. e. sixty to eighty shillings would have

In

Prism (Gr. píoμа, from πpiw, I saw). Dioptrics, a piece of glass or other diaphanous substance, more or less long, with triangular ends, employed to separate a ray of light into its constituent parts or colours by refraction. The prism is the instrument by means of which many of the remarkable phenomena of light and colours are exhibited. [CHROMATICS; OPTICS; REFRACTION.]

PRISM, In Geometry, a polyhedron, two of whose faces are equal, similar, and parallel, while all the rest are parallelograms. Prisms take particular names from the figures of their ends, or opposite equal and parallel sides. When the ends are triangles, they are called triangular prisms; when the ends are square, square prisms; when the ends are pentagonal, pentagonal prisms; and so on. A right prism has its sides perpendicular to its ends; an oblique prism is that of which the sides are oblique to the ends. The solid content of a prism is found by multiplying the area of the base into the perpendicular altitude; hence all prisms are to one another in the ratio compounded of their bases and altitudes. Prismatic Analysis. The resolution of a beam of light into its constituent rays of different refrangibility. [CHROMATICS; SPECTRUM ANALYSIS.]

Prismatic Colours. The colours produced by decomposing light by a prism. [PRIMARY COLOURS and CHROMATICS.]

Prismatic Compass. A surveying instrument, much used, on account of its convenient size and form, in military sketching, and for filling up the details of a map where

PRISON

consult the original article Prisons' in the Ency. Brit.; but the views of the author are somewhat too dogmatically expressed. The policy and practicability of making prison labour pay or contribute largely towards the maintenance of the prison has not been much discussed in England, where, from our less economical habits, the experiment has hardly been tried. In America several, it is said, afford a revenue to the state. (De Tocqueville, Du Système Pénitentiaire aux États-Unis.) In Belgium they have long been rendered very productive; the works of the present very able inspector-general, M. Ducpétiaux, contain ample information on the subject. It appears also, from various reports of the Irish prison inspectors, that the cost of work has been from time to time more than repaid by the return in every prison; but it does not appear clearly what is comprehended under the former head, and the numbers seem not altogether accurate.

By the Act 2 & 3 Vict. c. 56, separate confinement was for the first time distinguished from the severer punishment of solitary confinement, and the justices were empowered to make rules for classification, &c., subject to the approval of the secretary of state.

PRISONS, MAMERTINE or degree of offence, or in any other practicable occasional intervals of solitary confinement; mole, there will probably be some unusually the treadwheel being the most common species depraved characters; and then the experiment of labour. On this subject the reader may must fail. The only perfect classification is that which constitutes the basis of, 3. The separate system; namely, the entire separation of prisoners from each other in solitary cells. When this has been carried to excess as a means of punishment, namely, seclusion by day and by night, without labour, without employment, with only the occasional silent visits of the turnkey or the medical attendant, it has generally proved more than human nature can bear, at least for any co. siderable time; but separate confinement with labour as an alleviation, and with occasional visits for religious instruction, is a very different mode of treatment. The separate system was specially established in the great eastern penitentiary of Philadelphia, and in that of Glasgow. 4. The difficulty of enforcing solitary confinement, in some American prisons, seems to have led to the adoption of the silent system of which the prison at Auburn, in Pennsylvania, affords the most celebrated instance. The prisoners work together in the day, but are prevented from all communication: at night they are separate. It was, we believe, introduced several years ago in the Maison de Force at Ghent. In England, it is in operation at Coldbath Fields, Wakefield, and elsewhere. With respect to the comparative advantages of the two systems, the work of Messrs. Beaumont and De Tocqueville may be consulted for an impartial summary of evidence, without the expression of decided opinion. (Part i. chap. ii. 5.3.) The chief objections to the separate system are: (1) As a punishment, its inequality, being felt far more severely by some than others; but to this it may be answered, that those who do feel it are precisely those whom it is most desirable to affect-the more depraved. (2) Its effects on the mind and passions; a very difficult and delicate subject, and by far the most serious charge against it. (3) That even as a system of reform, for which, in subjects presenting any prospect of amendment, it is best calculated, it is utterly useless in short terms of imprisonment. To the silent system, its enemies object: (1) The extreme difficulty of carrying it into successful operation. (2) Its supposed effect in irritating, degrading, and even brutalising the minds of prisoners, by its vexatious discipline. They appeal in support of this position to the quantity of punishment (corporeal, or by solitary confinement) which is required to carry it into effect. 5. With respect to the introduction of labour into prisons of punishment, the chief question seems to be, whether it ought to form part of the punishment, and be of a vexatious and severe nature; or whether it should be used as an alleviation to the rigour of separate confinement and preparation of the criminal for re-entrance into society. The former is the principle commonly adopted in England; the ordinary sentence, for many offences, being imprisonment with hard labour, and with

The discontinuance of transportation, except to a very limited extent in 1853, and the substitution of the punishment of penal servitude, made prison discipline a matter of even more importance than it had previously been. The result of observation of the separate system in the model prison at Pentonville ended in its being reduced to nine months for men and a year for women (1854), except in cases of short sentences of one or two years, it being held that the whole of a short imprisonment might be beneficially passed in this manner. The labour of prisoners has been devoted, as far as practicable, to the construction of public works. In 1857, after much oscillation of opinion, the principle of remitting part of the sentence for good behaviour was adopted by government: a scale of remissions being introduced in proportion to the length of the sentence. The Irish system of convict discipline is said to go further in the direction of relaxation than the English, bringing the convicts nearer to the condition of free citizens.' For the latest discussions on this subject, see the Evidence appended to the Report on Secondary Punishments of the Commission of 1864; and for the system designed to effect the amendment of the juvenile criminal population in separate establishments, see REFORMATORY.

Prisons, Mamertine. Places of confinement in ancient Rome, chiefly intended for state prisoners. They were constructed of large uncemented stones; and, from the specimens of them which remain, it is difficult to imagine a more horrible place for the confinement of a human being. There were two apartments, one above the other, to which