On the Economy of Machinery and Manufactures Part 18

6. Another advantage, of no small importance, would be the total removal of all real or imaginary causes for combinations.

The workmen and the capitalist would so shade into each other-- would so evidently have a common interest, and their difficulties and distresses would be mutually so well understood that, instead of combining to oppress one another, the only combination which could exist would be a most powerful union between both parties to overcome their common difficulties.

314. One of the difficulties attending such a system is, that capitalists would at first fear to embark in it, imagining that the workmen would receive too large a share of the profits: and it is quite true that the workmen would have a larger share than at present: but, at the same time, it is presumed the effect of the whole system would be, that the total profits of the establishment being much increased, the smaller proportion allowed to capital under this system would yet be greater in actual amount, than that which results to it from the larger share in the system now existing.

315. It is possible that the present laws relating to partners.h.i.+ps might interfere with factories so conducted. If this interference could not be obviated by confining their purchases under the proposed system to ready money, it would be desirable to consider what changes in the law would be necessary to its existence: and this furnishes another reason for entering into the question of limited partners.h.i.+ps.

316. A difficulty would occur also in discharging workmen who behaved ill, or who were not competent to their work; this would arise from their having a certain interest in the reserved fund, and, perhaps, from their possessing a certain portion of the capital employed; but without entering into detail, it may be observed, that such cases might be determined on by meetings of the whole establishment; and that if the policy of the laws favoured such establishments, it would scarcely be more difficult to enforce just regulations, than it now is to enforce some which are unjust, by means of combinations either amongst the masters or the men.

317. Some approach to this system is already practised in several trades: the mode of conducting the Cornish mines has already been alluded to; the payment to the crew of whaling s.h.i.+ps is governed by this principle; the profits arising from fis.h.i.+ng with nets on the south coast of England are thus divided: one-half the produce belongs to the owner of the boat and net; the other half is divided in equal portions between the persons using it, who are also bound to a.s.sist in repairing the net when injured.

NOTES:

1. For a detailed account of the method of working the Cornish mines, see a paper of Mr John Taylor's Transactions of the Geological Society, vol. ii, p. 309.

Chapter 27

On Contriving Machinery

318. The power of inventing mechanical contrivances, and of combining machinery, does not appear, if we may judge from the frequency of its occurrence, to be a difficult or a rare gift. Of the vast mult.i.tude of inventions which have been produced almost daily for a series of years, a large part has failed from the imperfect nature of the first trials; whilst a still larger portion, which had escaped the mechanical difficulties, failed only because the economy of their operations was not sufficiently attended to.

The commissioners appointed to examine into the methods proposed for preventing the forgery of bank-notes, state in their report, that out of one hundred and seventy-eight projects communicated to the bank and to the commissioners, there were only twelve of superior skill, and nine which it was necessary more particularly to examine.

319. It is however a curious circ.u.mstance, that although the power of combining machinery is so common, yet the more beautiful combinations are exceedingly rare. Those which command our admiration equally by the perfection of their effects and the simplicity of their means, are found only amongst the happiest productions of genius.

To produce movements even of a complicated kind is not difficult. There exist a great mult.i.tude of known contrivances for all the more usual purposes, and if the exertion of moderate power is the end of the mechanism to be contrived, it is possible to construct the whole machine upon paper, and to judge of the proper strength to be given to each part as well as to the framework which supports it, and also of its ultimate effect, long before a single part of it has been executed. In fact, all the contrivance, and all the improvements, ought first to be represented in the drawings.

320. On the other hand, there are effects dependent upon physical or chemical properties for the determination of which no drawings will be of any use. These are the legitimate objects of direct trial. For example; if the ultimate result of an engine is to be that it shall impress letters on a copperplate by means of steel punches forced into it, all the mechanism by which the punches and the copper are to be moved at stated intervals, and brought into contact, is within the province of drawing, and the machinery may be arranged entirely upon paper. But a doubt may reasonably spring up, whether the bur that will be raised round the letter, which has been already punched upon the copper, may not interfere with the proper action of the punch for the letter which is to be punched next adjacent to it. It may also be feared that the effect of punching the second letter, if it be sufficiently near to the first, may distort the form of that first figure. If neither of these evils should arise, still the bur produced by the punching might be expected to interfere with the goodness of the impression produced by the copperplate; and the plate itself, after having all but its edge covered with figures, might change its form, from the unequal condensation which it must suffer in this process, so as to render it very difficult to take impressions from it at all. It is impossible by any drawings to solve difficulties such as these, experiment alone can determine their effect. Such experiments having been made, it is found that if the sides of the steel punch are nearly at right angles to the face of the letter, the bur produced is very inconsiderable; that at the depth which is sufficient for copperplate printing, no distortion of the adjacent letters takes place, although those letters are placed very close to each other; that the small bur which arises may easily be sc.r.a.ped off; and that the copperplate is not distorted by the condensation of the metal in punching, but is perfectly fit to print from, after it has undergone that process.

321. The next stage in the progress of an invention, after the drawings are finished and the preliminary experiments have been made, if any such should be requisite, is the execution of the machine itself. It can never be too strongly impressed upon the minds of those who are devising new machines, that to make the most perfect drawings of every part tends essentially both to the success of the trial, and to economy in arriving at the result. The actual execution from working drawings is comparatively an easy task; provided always that good tools are employed, and that methods of working are adopted, in which the perfection of the part constructed depends less on the personal skill of the workman, than upon the certainty of the method employed.

322. The causes of failure in this stage most frequently derive their origin from errors in the preceding one; and it is sufficient merely to indicate a few of their sources. They frequently arise from having neglected to take into consideration that metals are not perfectly rigid but elastic. A steel cylinder of small diameter must not be regarded as an inflexible rod; but in order to ensure its perfect action as an axis, it must be supported at proper intervals.

Again, the strength and stiffness of the framing which supports the mechanism must be carefully attended to. It should always be recollected, that the addition of superfluous matter to the immovable parts of a machine produces no additional momentum, and therefore is not accompanied with the same evil that arises when the moving parts are increased in weight. The stiffness of the framing in a machine produces an important advantage. If the bearings of the axis (those places at which they are supported) are once placed in a straight line, they will remain so, if the framing be immovable; whereas if the framework changes its form, though ever so slightly, considerable friction is immediately produced. This effect is so well understood in the districts where spinning factories are numerous, that, in estimating the expense of working a new factory, it is allowed that five per cent on the power of the steam-engine will be saved if the building is fireproof: for the greater strength and rigidity of a fireproof building prevents the movement of the long shafts or axes which drive the machinery, from being impeded by the friction that would arise from the slightest deviation in any of the bearings.

323. In conducting experiments upon machinery, it is quite a mistake to suppose that any imperfect mechanical work is good enough for such a purpose. If the experiment is worth making, it ought to be tried with all the advantages of which the state of mechanical art admits; for an imperfect trial may cause an idea to be given up, which better workmans.h.i.+p might have proved to be practicable. On the other hand, when once the efficiency of a contrivance has been established, with good workmans.h.i.+p it will be easy afterwards to ascertain the degree of perfection which will suffice for its due action.

324. It is partly owing to the imperfection of the original trials, and partly to the gradual improvements in the art of making machinery, that many inventions which have been tried, and given up in one state of art, have at another period been eminently successful. The idea of printing by means of moveable types had probably suggested itself to the imagination of many persons conversant with impressions taken either from blocks or seals. We find amongst the instruments discovered in the remains of Pompeii and Herculaneum, stamps for words formed out of one piece of metal, and including several letters. The idea of separating these letters, and of recombining them into other words, for the purpose of stamping a book, could scarcely have failed to occur to many: but it would almost certainly have been rejected by those best acquainted with the mechanical arts of that time; for the workmen of those days must have instantly perceived the impossibility of producing many thousand pieces of wood or metal, fitting so perfectly and ranging so uniformly, as the types or blocks of wood now used in the art of printing.

The principle of the press which bears the name of Bramah, was known about a century and a half before the machine, to which it gave rise, existed; but the imperfect state of mechanical art in the time of the discoverer, would have effectually deterred him, if the application of it had occurred to his mind, from attempting to employ it in practice as an instrument for exerting force.

These considerations prove the propriety of repeating, at the termination of intervals during which the art of making machinery has received any great improvement, the trails of methods which, although founded upon just principles, had previously failed.

325. When the drawings of a machine have been properly made, and the parts have been well executed, and even when the work it produces possesses all the qualities which were antic.i.p.ated, still the invention may fail; that is, it may fail of being brought into general practice. This will most frequently arise from the circ.u.mstance of its producing its work at a greater expense than that at which it can be made by other methods.

326. Whenever the new, or improved machine, is intended to become the basis of a manufacture, it is essentially requisite that the whole expense attending its operations should be fully considered before its construction is undertaken. It is almost always very difficult to make this estimate of the expense: the more complicated the mechanism, the less easy is the task; and in cases of great complexity and extent of machinery it is almost impossible. It has been estimated roughly, that the first individual of any newly invented machine, will cost about five times as much as the construction of the second, an estimate which is, perhaps, sufficiently near the truth. If the second machine is to be precisely like the first, the same drawings, and the same patterns will answer for it; but if, as usually happens, some improvements have been suggested by the experience of the first, these must be more or less altered. When, however, two or three machines have been completed, and many more are wanted, they can usually be produced at much less than one-fifth of the expense of the original invention.

327. The arts of contriving, of drawing, and of executing, do not usually reside in their greatest perfection in one individual; and in this, as in other arts, the division of labour must be applied. The best advice which can be offered to a projector of any mechanical invention, is to employ a respectable draughtsman; who, if he has had a large experience in his profession, will a.s.sist in finding out whether the contrivance is new, and can then make working drawings of it. The first step, however, the ascertaining whether the contrivance has the merit of novelty, is most important; for it is a maxim equally just in all the arts, and in every science, that the man who aspires to fortune or to fame by new discoveries, must be content to examine with care the knowledge of his contemporaries, or to exhaust his efforts in inventing again, what he will most probably find has been better executed before.

328. This, nevertheless, is a subject upon which even ingenious men are often singularly negligent. There is, perhaps, no trade or profession existing in which there is so much quackery, so much ignorance of the scientific principles, and of the history of their own art, with respect to its resources and extent, as are to be met with amongst mechanical projectors. The self-const.i.tuted engineer, dazzled with the beauty of some, perhaps, really original contrivance, a.s.sumes his new profession with as little suspicion that previous instruction, that thought and painful labour, are necessary to its successful exercise, as does the statesman or the senator. Much of this false confidence arises from the improper estimate which is entertained of the difficulty of invention in mechanics. It is, therefore, of great importance to the individuals and to the families of those who are too often led away from more suitable pursuits, the dupes of their own ingenuity and of the popular voice, to convince both them and the public that the power of making new mechanical combinations is a possession common to a mult.i.tude of minds, and that the talents which it requires are by no means of the highest order. It is still more important that they should be impressed with the conviction that the great merit, and the great success of those who have attained to eminence in such matters, was almost entirely due to the unremitted perseverance with which they concentrated upon their successful inventions the skill and knowledge which years of study had matured.

Chapter 28

Proper Circ.u.mstances for the Application of Machinery

329. The first object of machinery, the chief cause of its extensive utility, is the perfection and the cheap production of the articles which it is intended to make. Whenever it is required to produce a great mult.i.tude of things, all of exactly the same kind, the proper time has arrived for the construction of tools or machines by which they may be manufactured. If only a few pairs of cotton stockings should be required, it would be an absurd waste of time, and of capital, to construct a stocking-frame to weave them, when, for a few pence, four steel wires can be procured by which they may be knit. If, on the other hand, many thousand pairs were wanted, the time employed, and the expense incurred in constructing a stocking-frame, would be more than repaid by the saving of time in making that large number of stockings. The same principle is applicable to the copying of letters: if three or four copies only are required, the pen and the human hand furnish the cheapest means of obtaining them; if hundreds are called for, lithography may be brought to our a.s.sistance; but if hundreds of thousands are wanted, the machinery of a printing establishment supplies the most economical method of accomplis.h.i.+ng the object.

330. There are, however, many cases in which machines or tools must be made, in which economical production is not the most important object. Whenever it is required to produce a few articles parts of machinery, for instance, which must be executed with the most rigid accuracy or be perfectly alike--it is nearly impossible to fulfil this condition, even with the aid of the most skilful hands: and it becomes necessary to make tools expressly for the purpose, although those tools should, as frequently happens, cost more in constructing than the things they are destined to make.

331. Another instance of the just application of machinery, even at an increased expense, arises where the shortness of time in which the article is produced, has an important influence on its value. In the publication of our daily newspapers, it frequently happens that the debates in the Houses of Parliament are carried on to three and four o'clock in the morning, that is.

to within a very few hours of the time for the publication of the paper. The speeches must be taken down by reporters, conveyed by them to the establishment of the newspaper, perhaps at the distance of one or two miles, transcribed by them in the office, set up by the compositor, the press corrected, and the paper be printed off and distributed, before the public can read them.

Some of these journals have a circulation of from five to ten thousand daily. Supposing four thousand to be wanted, and that they could be printed only at the rate of five hundred per hour upon one side of the paper, (which was the greatest number two journeymen and a boy could take off by the old hand presses), sixteen hours would be required for printing the complete edition; and the news conveyed to the purchasers of the latest portion of the impression, would be out of date before they could receive it. To obviate this difficulty, it was often necessary to set up the paper in duplicate, and sometimes, when late, in triplicate: but the improvements in the printing machines have been so great, that four thousand copies are now printed on one side in an hour.

332. The establishment of 'The Times' newspaper is an example, on a large scale, of a manufactory in which the division of labour, both mental and bodily, is admirably ill.u.s.trated, and in which also the effect of domestic economy is well exemplified.

It is scarcely imagined by the thousands who read that paper in various quarters of the globe, what a scene of organized activity the factory presents during the whole night, or what a quant.i.ty of talent and mechanical skill is put in action for their amus.e.m.e.nt and information. (1*) Nearly a hundred persons are employed in this establishment; and, during the session of Parliament, at least twelve reporters are constantly attending the Houses of Commons and Lords; each in his turn retiring, after about an hour's work, to translate into ordinary writing, the speech he has just heard and noted in shorthand. In the meantime fifty compositors are constantly at work, some of whom have already set up the beginning, whilst others are committing to type the yet undried ma.n.u.script of the continuation of a speech, whose middle portion is travelling to the office in the pocket of the hasty reporter, and whose eloquent conclusion is, perhaps, at that very moment, making the walls of St Stephen's vibrate with the applause of its hearers. These congregated types, as fast as they are composed, are pa.s.sed in portions to other hands; till at last the scattered fragments of the debate, forming, when united with the ordinary matter, eight-and-forty columns, reappear in regular order on the platform of the printing-press. The hand of man is now too slow for the demands of his curiosity, but the power of steam comes to his a.s.sistance. Ink is rapidly supplied to the moving types, by the most perfect mechanism; four attendants incessantly introduce the edges of large sheets of white paper to the junction of two great rollers, which seem to devour them with unsated appet.i.te; other rollers convey them to the type already inked, and having brought them into rapid and successive contact, redeliver them to four other a.s.sistants, completely printed by the almost momentary touch. Thus, in one hour, four thousand sheets of paper are printed on one side; and an impression of twelve thousand copies, from above three hundred thousand moveable pieces of metal, is produced for the public in six hours.

333. The effect of machinery in printing other periodical publications, and of due economy in distributing them, is so important for the interests of knowledge, that it is worth examining by what means it is possible to produce them at the small price at which they are sold. 'Chambers' Journal', which is published at Edinburgh, and sold at three halfpence a number, will furnish an example. Soon after its commencement in 1832, the sale in Scotland reached 30,000, and in order to supply the demand in London it was reprinted; but on account of the expense of 'composition' it was found that this plan would not produce any profit, and the London edition was about to be given up, when it occurred to the proprietor to stereotype it at Edinburgh, and cast two copies of the plates. This is now done about three weeks before the day of publication--one set of plates being sent up to London by the mail, an impression is printed off by steam: the London agent has then time to send packages by the cheapest conveyances to several of the large towns, and other copies go through the booksellers' parcels to all the smaller towns. Thus a great saving is effected in the outlay of capital, and 20,000 copies are conveyed from London, as a centre, to all parts of England, whilst there is no difficulty in completing imperfect sets, nor any waste from printing more than the public demand.

334. The conveyance of letters is another case, in which the importance of saving time would allow of great expense in any new machinery for its accomplishment. There is a natural limit to the speed of horses, which even the greatest improvements in the breed, aided by an increased perfection in our roads, can never surpa.s.s; and from which, perhaps, we are at present not very remote. When we reflect upon the great expense of time and money which the last refinements of a theory or an art usually require, it is not unreasonable to suppose that the period has arrived in which the subst.i.tution of machinery for such purposes ought to be tried.

335. The post bag despatched every evening by the mail to one of our largest cities, Bristol, usually weighs less than a hundred pounds. Now, the first reflection which naturally presents itself is, that, in order to transport these letters a hundred and twenty miles, a coach and apparatus, weighing above thirty hundredweight, are put in motion, and also conveyed over the same s.p.a.ce. (2*)

It is obvious that, amongst the conditions of machinery for accomplis.h.i.+ng such an object, it would be desirable to reduce the weight of matter to be conveyed along with the letters: it would also be desirable to reduce the velocity of the animal power employed; because the faster a horse is driven, the less weight he can draw. Amongst the variety of contrivances which might be imagined for this purpose, we will mention one, which, although by no means free from objections, fulfils some of the prescribed conditions; and it is not a purely theoretical speculation, since some few experiments have been made upon it, though on an extremely limited scale.

336. Let us imagine a series of high pillars erected at frequent intervals, perhaps every hundred feet, and as nearly as possible in a straight line between two post towns. An iron or steel wire must be stretched over proper supports, fixed on each of these pillars, and terminating at the end of every three or five miles, as may be found expedient, in a very strong support, by which it may be stretched. At each of these latter points a man ought to reside in a small stationhouse. A narrow cylindrical tin case, to contain the letters, might be suspended by two wheels rolling upon this wire; the cases being so constructed as to enable the wheels to pa.s.s unimpeded by the fixed supports of the wire. An endless wire of much smaller size must pa.s.s over two drums, one at each end of the station. This wire should be supported on rollers, fixed to the supports of the great wire, and at a short distance below it. There would thus be two branches of the smaller wire always accompanying the larger one; and the attendant at either station, by turning the drum, might cause them to move with great velocity in opposite directions. In order to convey the cylinder which contains the letters, it would only be necessary to attach it by a string, or by a catch, to either of the branches of the endless wire. Thus it would be conveyed speedily to the next station, where it would be removed by the attendant to the commencement of the next wire, and so forwarded. It is unnecessary to enter into the details which this, or any similar plan, would require. The difficulties are obvious; but if: these could be overcome, it would present many advantages besides velocity; for if an attendant resided at each station, the additional expense of having two or three deliveries of letters every day, and even of sending expresses at any moment, would be comparatively trifling; nor is it impossible that the stretched wire might itself be available for a species of telegraphic communication yet more rapid.

Perhaps if the steeples of churches, properly selected, were made use of, connecting them by a few intermediate stations with some great central building, as, for instance, with the top of St Paul's; and if a similar apparatus were placed on the top of each steeple, with a man to work it during the day, it might be possible to diminish the expense of the two-penny post, and make deliveries every half hour over the greater part of the metropolis.

337. The power of steam, however, bids fair almost to rival the velocity of these contrivances; and the fitness of its application to the purposes of conveyance, particularly where great rapidity is required, begins now to be generally admitted.

The following extract from the Report of the Committee of the House of Commons on steamcarriages, explains clearly its various advantages:

Perhaps one of the princ.i.p.al advantages resulting from the use of steam, will be, that it may be employed as cheaply at a quick as at a slow rate; 'this is one of the advantages over horse labour.

which becomes more and more expensive as the speed is increased.

There is every reason to expect, that in the end the rate of travelling by steam will be much quicker than the utmost speed of travelling by horses; in short, the safety to travellers will become the limit to speed.' In horse-draught the opposite result takes place; 'in all cases horses lose power of draught in a much greater proportion than they gain speed, and hence the work they do becomes more expensive as they go quicker.'

Without increase of cost, then, we shall obtain a power which will insure a rapidity of internal communication far beyond the utmost speed of horses in draught; and although the performance of these carriages may not have hitherto attained this point, when once it has been established, that at equal speed we can use steam more cheaply in draught than horses, we may fairly antic.i.p.ate that every day's increased experience in the management of the engines, will induce greater skill, greater confidence, and greater speed.

The cheapness of the conveyance will probably be, for some time, a secondary consideration. If, at present, it can be used as cheaply as horse power, the compet.i.tion with the former modes of conveyance will first take place as to speed. When once the superiority of steam-carriages shall have been fully established, compet.i.tion will induce economy in the cost of working them. The evidence, however, of Mr Macneill, shewing the greater efficiency, with diminished expenditure of fuel, by locomotive engines on railwavs, convinces the committee, that experience will soon teach a better construction of the engines, and a less costly mode of generating the requisite supply of steam.

Nor are the advantages of steam-power confined to the greater velocitv attained, or to its greater cheapness than horse-draught. In the latter, danger is increased, in as large a proportion as expense, by greater speed. In steam-power, on the contrary, 'there is no danger of being run away with, and that of being overturned is greatly diminished. It is difficult to control four such horses as can draw a heavy carriage ten miles per hour, in case they are frightened, or choose to run away; and for quick travelling they must be kept in that state of courage, that they are always inclined for running away, particularly down hills, and at sharp turns of the road. In steam, however, there is little corresponding danger, being perfectly controllable, and capable of exerting its power in reverse in going down hills., Every witness examined has given the fullest and most satisfactory evidence of the perfect control which the conductor has over the movement of the carriage. With the slightest exertion it can be stopped or turned, under circ.u.mstances where horses would be totally unmanageable.

338. Another instance may be mentioned in which the object to be obtained is so important, that although it might be rarely wanted, yet machinery for that purpose would justify considerable expense. A vessel to contain men, and to be navigated at some distance below the surface of the sea, would, in many circ.u.mstances, be almost invaluable. Such a vessel, evidently, could not be propelled by any engine requiring the aid of fire.

If, however, by condensing air into a liquid, and carrying it in that state, a propelling power could be procured sufficient for moving the vessel through a considerable s.p.a.ce, the expense would scarcely render its occasional employment impossible.(3*)

339. Slide of Alpnach. Amongst the forests which flank many of the lofty mountains of Switzerland, some of the finest timber is found in positions almost inaccessible. The expense of roads, even if it were possible to make them in such situations, would prevent the inhabitants from deriving any advantages from these almost inexhaustible supplies. Placed by nature at a considerable elevation above the spot at which they can be made use of, they are precisely in fit circ.u.mstances for the application of machinery to their removal; and the inhabitants avail themselves of the force of gravity to relieve them from some portion of this labour. The inclined planes which they have established in various forests, by which the timber has been sent down to the water courses, have excited the admiration of every traveller; and in addition to the merit of simplicity, the construction these slides requires scarcely anything beyond the material which grows upon the spot.