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Joseph Clement was born at Great Ashby in Westmoreland, in the year 1779. His father was a hand-loom weaver, and a man of remarkable culture considering his humble station in life. He was an ardent student of natural history, and possessed a much more complete knowledge of several sub-branches of that science than was to have been looked for in a common working-man. One of the departments which he specially studied was Entomology. In his leisure hours he was accustomed to traverse the country searching the hedge-bottoms for beetles and other insects, of which he formed a remarkably complete collection; and the capture of a rare specimen was quite an event in his life. In order more deliberately to study the habits of the bee tribe, he had a number of hives constructed for the purpose of enabling him to watch their proceedings without leaving his work; and the pursuit was a source of the greatest pleasure to him. He was a lover of all dumb creatures; his cottage was haunted by birds which flew in and out at his door, and some of them became so tame as to hop up to him and feed out of his hand. "Old Clement" was also a bit of a mechanic, and such of his leisure moments as he did not devote to insect-hunting, were employed in working a lathe of his own construction, which he used to turn his bobbing on, and also in various kinds of amateur mechanics.
His boy Joseph, like other poor men's sons, was early set to work. He received very little education, and learnt only the merest rudiments of reading and writing at the village school. The rest of his education he gave to himself as he grew older. His father needed his help at the loom, where he worked with him for some years; but, as handloom weaving was gradually being driven out by improved mechanism, the father prudently resolved to put his son to a better trade. They have a saying in Cumberland that when the bairns reach a certain age, they are thrown on to the house-rigg, and that those who stick on are made thatchers of, while those who fall off are sent to St. Bees to be made parsons of. Joseph must have been one of those that stuck on - at all events his father decided to make him a thatcher, afterwards a slater, and he worked at that trade for five years, between eighteen and twenty-three.
The son, like the father, had a strong liking for mechanics, and as the slating trade did not keep him in regular employment, especially in winter time, he had plenty of opportunity for following the bent of his inclinations. He made a friend of the village blacksmith, whose smithy he was accustomed to frequent, and there he learned to work at the forge, to handle the hammer and file, and in a short time to shoe horses with considerable expertness. A cousin of his named Farer, a clock and watchmaker by trade, having returned to the village from London, brought with him some books on mechanics, which he lent to Joseph to read; and they kindled in him an ardent desire to be a mechanic instead of a slater. He nevertheless continued to maintain himself by the latter trade for some time longer, until his skill had grown; and, by way of cultivating it, he determined, with the aid of his friend the village blacksmith, to make a turning-lathe. The two set to work, and the result was the production of an article in every way superior to that made by Clement's father, which was accordingly displaced to make room for the new machine. It was found to work very satisfactorily, and by its means Joseph proceeded to turn fifes, flutes, clarinets, and hautboys; for to his other accomplishments he joined that of music, and could play upon the instruments that he made. One of his most ambitious efforts was the making of a pair of Northumberland bagpipes, which he finished to his satisfaction, and performed upon to the great delight of the villagers. To assist his father in his entomological studies, he even contrived, with the aid of the descriptions given in the books borrowed from his cousin the watchmaker, to make for him a microscope, from which he proceeded to make a reflecting telescope, which proved a very good instrument. At this early period (1804) he also seems to have directed his attention to screw-making, a branch of mechanics in which he afterwards became famous; and he proceeded to make a pair of very satisfactory die-stocks, though it is said that he had not before seen or even heard of such a contrivance for making screws.
So clever a workman was not likely to remain long a village slater. Although the ingenious pieces of work which he turned out by his lathe did not bring him in much money, he liked the occupation so much better than slating that he was gradually giving up that trade. His father urged him to stick to slating as "a safe thing;" but his own mind was in favour of following his instinct to be a mechanic; and at length he determined to leave his village and seek work in a new line. He succeeded in finding employment in a small factory at Kirby Stephen, a town some thirteen miles from Great Ashby, where he worked at making power-looms. From an old statement of account against his employer which we have seen, in his own handwriting, dated the 6th September, 1805, it appears that his earnings at such work as "fitting the first set of iron loames," "fitting up shittles," and "making moddles," were 3s. 6d. a day; and he must, during the same time, have lived with his employer, who charged him as a set-off "14 weaks bord at 8s. per weak." He afterwards seems to have worked at piece-work in partnership with one Andrew Gamble supplying the materials as well as the workmanship for the looms and shuttles. His employer, Mr. George Dickinson, also seems to have bought his reflecting telescope from him for the sum of 12L.
From Kirby Stephen Clement removed to Carlisle, where he was employed by Forster and Sons during the next two years at the same description of work; and he conducted himself, according; to their certificate on his leaving their employment to proceed to Glasgow in 1807, "with great sobriety and industry, entirely to their satisfaction."
While working at Glasgow as a turner, he took lessons in drawing from Peter Nicholson, the well-known writer on carpentry - a highly ingenious man. Nicholson happened to call at the shop at which Clement worked in order to make a drawing of a power-loom; and Clement's expressions of admiration at his expertness were so enthusiastic, that Nicholson, pleased with the youth's praise, asked if he could be of service to him in any way. Emboldened by the offer, Clement requested, as the greatest favour he could confer upon him, to have the loan of the drawing he had just made, in order that he might copy it. The request was at once complied with; and Clement, though very poor at the time, and scarcely able to buy candle for the long winter evenings, sat up late every night until he had finished it. Though the first drawing he had ever made, he handed it back to Nicholson instead of the original, and at first the draughtsman did not recognise that the drawing was not his own. When Clement told him that it was only the copy, Nicholson's brief but emphatic praise was - "Young man, you’ll do!" Proud to have such a pupil, Nicholson generously offered to give him gratuitous lessons in drawing, which were thankfully accepted; and Clement, working at nights with great ardour, soon made rapid progress, and became an expert draughtsman.
Trade being very slack in Glasgow at the time, Clement, after about a year's stay in the place, accepted a situation with Messrs. Leys, Masson, and Co., of Aberdeen, with whom he began at a guinea and a half a week, from which he gradually rose to two guineas, and ultimately to three guineas. His principal work consisted in designing and making power-looms for his employers, and fitting them up in different parts of the country.
He continued to devote himself to the study of practical mechanics, and made many improvements in the tools with which he worked. While at Glasgow he had made an improved pair of die-stocks for screws; and, at Aberdeen, he made a turning-lathe with a sliding mandrill and guide-screws, for cutting screws, furnished also with the means for correcting guide-screws. In the same machine he introduced a small slide rest, into which he fixed the tool for cutting the screws, - having never before seen a slide rest, though it is very probable he may have heard of what Maudslay had already done in the same direction. Clement continued during this period of his life an industrious self-cultivator, occupying most of his spare hours in mechanical and landscape drawing, and in various studies.
Among the papers left behind him we find a ticket to a course of instruction on Natural Philosophy given by Professor Copland in the Marischal College at Aberdeen, which Clement attended in the session of 1812-13; and we do not doubt that our mechanic was among the most diligent of his pupils. Towards the end of 1813, after saving about 100L out of his wages, Clement resolved to proceed to London for the purpose of improving himself in his trade and pushing his way in the world. The coach by which he travelled set him down in Snow Hill, Holborn; and his first thought was of finding work. He had no friend in town to consult on the matter, so he made inquiry of the coach-guard whether he knew of any person in the mechanical line in that neighbourhood. The guard said, "Yes; there was Alexander Galloway's show shop, just round the corner, and he employed a large number of hands." Running round the corner, Clement looked in at Galloway's window, through which he saw some lathes and other articles used in machine shops. Next morning he called upon the owner of the shop to ask employment. "What can you do?" asked Galloway. "I can work at the forge," said Clement. "Anything else?" "I can turn." "What else?" "I can draw." "What!" said Galloway, "can you draw? Then I will engage you." A man who could draw or work to a drawing in those days was regarded as a superior sort of mechanic. Though Galloway was one of the leading tradesmen of his time, and had excellent opportunities for advancement, he missed them all. As Clement afterwards said of him, "He was only a mouthing common-council man, the height of whose ambition was to be an alderman;" and, like most corporation celebrities, he held a low rank in his own business. He very rarely went into his workshops to superintend or direct his workmen, leaving this to his foremen, a sufficient indication of the causes of his failure as a mechanic.*
On one occasion Galloway had a cast-iron roof made for his workshop, so flat and so independent of ties that the wonder was that it should have stood an hour. One day Peter Keir, an engineer much employed by the government - a clever man, though some what eccentric - was taken into the shop by Galloway to admire the new roof. Keir, on glancing up at it, immediately exclaimed, "Come outside, and let us speak about it there!" All that he could say to Galloway respecting the unsoundness of its construction was of no avail. The fact was that, however Keir might argue about its not being able to stand, there it was actually standing, and that was enough for Galloway. Keir went home, his mind filled with Galloway's most unprincipled roof. "If that stands," said he to himself, "all that I have been learning and doing for thirty years has been wrong." That night he could not sleep for thinking about it. In the morning he strolled up Primrose Hill, and returned home still muttering to himself about "that roof." "What, said his wife to him, "are you thinking of Galloway's roof?" "Yes, said he. "Then you have seen the papers?" "No -- what about them?" "Galloway's roof has fallen in this morning, and killed eight or ten of the men!" Keir immediately went to bed, and slept soundly till next morning.
On entering Galloway's shop, Clement was first employed in working at the lathe; but finding the tools so bad that it was impossible to execute satisfactory work with them, he at once went to the forge, and began making a new set of tools for himself. The other men, to whom such a proceeding was entirely new, came round him to observe his operations, and they were much struck with his manual dexterity. The tools made, he proceeded to use them, displaying what seemed to the other workmen an unusual degree of energy and intelligence; and some of the old hands did not hesitate already to pronounce Clement to be the best mechanic in the shop. When Saturday night came round, the other men were curious to know what wages Galloway would allow the new hand; and when he had been paid, they asked him. "A guinea," was the reply. "A guinea! Why, you are worth two if you are worth a shilling," said an old man who came out of the rank - an excellent mechanic, who, though comparatively worthless through his devotion to drink, knew Clement's money value to his employer better than any man there; and he added, "Wait for a week or two, and if you are not better paid than this, I can tell you of a master who will give you a fairer wage." Several Saturdays came round, but no advance was made on the guinea a week; and then the old workman recommended Clement to offer himself to Bramah at Pimlico, who was always on the look out for first-rate mechanics.
Clement acted on the advice, and took with him some of his drawings, at sight of which Joseph Bramah immediately engaged him for a month; and at the end of that time he had given so much satisfaction, that it was agreed he should continue for three months longer at two guineas a week. Clement was placed in charge of the tools of the shop, and he showed himself so apt at introducing improvements in them, as well as in organizing the work with a view to despatch and economy, that at the end of the term Bramah made him a handsome present, adding, "if I had secured your services five years since, I would now have been a richer man by many thousands of pounds." A formal agreement for a term of five years was then entered into between Bramah and Clement, dated the 1st of April, 1814, by which the latter undertook to fill the office of chief-draughtsman and superintendent of the Pimlico Works, in consideration of a salary of three guineas a week, with an advance of four shillings a week in each succeeding year of the engagement. This arrangement proved of mutual advantage to both. Clement devoted himself with increased zeal to the improvement of the mechanical arrangements of the concern, exhibiting his ingenuity in many ways, and taking; a genuine pride in upholding the character of his master for turning out first-class work.
On the death of Bramah, his sons returned from college and entered into possession of the business. They found Clement the ruling mind there and grew jealous of him to such an extent that his situation became uncomfortable; and by mutual consent he was allowed to leave before the expiry of his term of agreement. He had no difficulty in finding employment; and was at once taken on as chief draughtsman at Maudslay and Field's where he was of much assistance in proportioning the early marine engines, for the manufacture of which that firm were becoming celebrated. After a short time, he became desirous of beginning business on his own account as a mechanical engineer. He was encouraged to do this by the Duke of Northumberland, who, being a great lover of mechanics and himself a capital turner, used often to visit Maudslay's, and thus became acquainted with Clement, whose expertness as a draughtsman and mechanic he greatly admired. Being a man of frugal and sober habits, always keeping his expenditure very considerably within his income, Clement had been enabled to accumulate about 500L, which he thought would be enough for his purpose; and he accordingly proceeded, in 1817, to take a small workshop in Prospect Place, Newington Butts, where he began business as a mechanical draughtsman and manufacturer of small machinery requiring first-class workmanship.
From the time when he took his first gratuitous lessons in drawing from Peter Nicholson, at Glasgow, in 1807, he had been steadily improving in this art, the knowledge of which is indispensable to whoever aspires to eminence as a mechanical engineer, until by general consent Clement was confessed to stand unrivalled as a draughtsman. Some of the very best drawings contained in the Transactions of the Society of Arts, from the year 1817 downwards, especially those requiring the delineation of any unusually elaborate piece of machinery, proceeded from the hand of Clement. In some of these, he reached a degree of truth in mechanical perspective which has never been surpassed.
To facilitate his labours, he invented an extremely ingenious instrument, by means of which ellipses of all proportions, as well as circles and right lines, might be geometrically drawn on paper or on copper. He took his idea of this instrument from the trammel used by carpenters for drawing imperfect ellipses; and when he had succeeded in avoiding the crossing of the points, he proceeded to invent the straight-line motion. For this invention the Society of Arts awarded him their gold medal in 1818. Some years later, he submitted to the same Society his invention of a stand for drawings of large size. He had experienced considerable difficulty in making such drawings, and with his accustomed readiness to overcome obstacles, he forthwith set to work and brought out his new drawing-table.
As with many other original-minded mechanics, invention became a habit with him, and by study and labour he rarely failed in attaining the object which he had bent his mind upon accomplishing. Indeed, nothing pleased him better than to have what he called "a tough job;" as it stimulated his inventive faculty, in the exercise of which he took the highest pleasure. Hence mechanical schemers of all kinds were accustomed to resort to Clement for help when they had found an idea which they desired to embody in a machine. If there was any value in their idea, none could be more ready than he to recognise its merit, and to work it into shape; but if worthless, he spoke out his mind at once, dissuading the projector from wasting upon it further labour or expense.
One of the important branches of practical mechanics to which Clement continued through life to devote himself, was the improvement of self-acting tools, more especially of the slide-lathe. He introduced various improvements in its construction and arrangement, until in his hands it became as nearly perfect as it was possible to be. In 1818, he furnished the lathe with a slide rest twenty-two inches long, for the purpose of cutting screws, provided with the means of self-correction; and some years later, in 1827, the Society of Arts awarded him their gold Isis medal for his improved turning-lathe, which embodied many ingenious contrivances calculated to increase its precision and accuracy in large surface-turning.
The beautiful arrangements embodied in Mr. Clement's improved lathe can with difficulty be described in words; but its ingenuity may be inferred from a brief statement of the defects which it was invented to remedy, and which it successfully overcame. When the mandrill of a lathe, having a metal plate fixed to it, turns round with a uniform motion, and the slide rest which carries the cutter is moving from the circumference of the work to the centre, it will be obvious that the quantity of metal passing over the edge of the cutter at each revolution, and therefore at equal intervals of time, is continually diminishing, in exact proportion to the spiral line described by the cutter on the face of the work. But in turning metal plates it is found very in expedient to increase the speed of the work beyond a certain quantity; for when this happens, and the tool passes the work at too great a velocity, it heats, softens, and is ground away, the edge of the cutter becomes dull, and the surface of the plate is indented and burnished, instead of being turned. Hence loss of time on the part of the workman, and diminished work on the part of the tool, results which, considering the wages of the one and the capital expended on the construction of the other, are of no small importance; for the prime objects of all improvement of tools are, economy of time and economy of capital to minimize labour and cost, and maximize result.
The defect to which we have referred was almost the only remaining imperfection in the lathe, and Mr. Clement overcame it by making the machine self-regulating; so that, whatever might be the situation of the cutter, equal quantities of metal should pass over it in equal times, - the speed at the centre not exceeding that suited to the work at the circumference, - while the workman was enabled to convert the varying rate of the mandrill into a uniform one whenever he chose. Thus the expedients of wheels, riggers, and drums, of different diameters, by which it had been endeavoured to alter the speed of the lathe-mandrill, according to the hardness of the metal and the diameter of the thing to be turned, were effectually disposed of. These, though answering very well where cylinders of equal diameter had to be bored, and a uniform motion was all that was required, were found very inefficient where a Plane surface had to be turned; and it was in such cases that Mr. Clement's lathe was found so valuable. By its means surfaces of unrivalled correctness were produced, and the slide-lathe, so improved, became recognised and adopted as the most accurate and extensively applicable of all machine-tools.
The year after Mr. Clement brought out his improved turning-lathe, he added to it his self-adjusting double driving centre-chuck, for which the Society of Arts awarded him their silver medal in 1828. In introducing this invention to the notice of the Society, Mr. Clement said, "Although I have been in the habit of turning and making turning-lathes and other machinery for upwards of thirty-five years, and have examined the best turning-lathes in the principal manufactories throughout Great Britain, I find it universally regretted by all practical men that they cannot turn anything perfectly true between the centres of the lathe." It was found by experience, that there was a degree of eccentricity, and consequently of imperfection, in the figure of any long cylinder turned while suspended between the centres of the lathe, and made to revolve by the action of a single driver. Under such circumstances the pressure of the tool tended to force the work out of the right line and to distribute the strain between the driver and the adjacent centre, so that one end of the cylinder became eccentric with respect to the other. By Mr. Clement's invention of the two-armed driver, which was self-adjusting, the strain was taken from the centre and divided between the two arms, which being equidistant from the centre, effectually corrected all eccentricity in the work. This invention was found of great importance in ensuring the true turning of large machinery, which before had been found a matter of considerable difficulty.
In the same year (1828) Mr. Clement began the making of fluted taps and dies, and he established a mechanical practice with reference to the pitch of the screw, which proved of the greatest importance in the economics of manufacture. Before his time, each mechanical engineer adopted a thread of his own; so that when a piece of work came under repair, the screw-hob had usually to be drilled out, and a new thread was introduced according to the usage which prevailed in the shop in which the work was executed. Mr. Clement saw a great waste of labour in this practice, and he promulgated the idea that every screw of a particular length ought to be furnished with its appointed number of threads of a settled pitch. Taking the inch as the basis of his calculations, he determined the number of threads in each case; and the practice thus initiated by him, recommended as it was by convenience and economy, was very shortly adopted throughout the trade. It may be mentioned that one of Clement's ablest journeymen, Mr. Whitworth, has, since his time, been mainly instrumental in establishing the settled practice; and Whitworth's thread (initiated by Clement) has become recognised throughout the mechanical world. To carry out his idea, Clement invented his screw-engine lathe, with gearing, mandrill, and sliding-table wheel-work, by means of which he first cut the inside screw-tools from the left-handed hobs - the reverse mode having before been adopted, - while in shaping machines he was the first to use the revolving cutter attached to the slide rest.
Then, in 1828, he fluted the taps for the first time with a revolving cutter, -other makers having up to that time only notched them. Among his other inventions in screws may be mentioned his headless tap, which, according to Mr. Nasmyth, is so valuable an invention, that, "if he had done nothing else, it ought to immortalize him among mechanics. It passed right through the hole to be tapped, and was thus enabled to do the duty of three ordinary screws." By these improvements much greater precision was secured in the manufacture of tools and machinery, accompanied by a greatly reduced cost of production; the results of which are felt to this day.
Another of Mr. Clement's ingenious inventions was his Planing Machine, by means of which metal plates of large dimensions were planed with perfect truth and finished with beautiful accuracy. There is perhaps scarcely a machine about which there has been more controversy than this; and we do not pretend to be able to determine the respective merits of the many able mechanics who have had a hand in its invention. It is exceedingly probable that others besides Clement worked out the problem in their own way, by independent methods; and this is confirmed by the circumstance that though the results achieved by the respective inventors were the same, the methods employed by them were in many respects different. As regards Clement, we find that previous to the year 1820 he had a machine in regular use for planing the triangular bars of lathes and the sides of weaving-looms. This instrument was found so useful and so economical in its working, that Clement proceeded to elaborate a planing machine of a more complete kind, which he finished and set to work in the year 1825. He prepared no model of it, but made it direct from the working drawings; and it was so nicely constructed, that when put together it went without a hitch, and has continued steadily working for more than thirty years down to the present day.
Clement took out no patent for his invention, relying for protection mainly on his own and his workmen's skill in using it. We therefore find no specification of his machine at the Patent Office, as in the case of most other capital inventions; but a very complete account of it is to be found in the Transactions of the Society of Arts for 1832, as described by Mr. Varley. The practical value of the Planing Machine induced the Society to apply to Mr. Clement for liberty to publish a full description of it; and Mr. Varley's paper was the result.
It may be briefly stated that this engineer's plane differs greatly from the carpenter's plane, the cutter of which is only allowed to project so far as to admit of a thin shaving to be sliced off, the plane working flat in proportion to the width of the tool, and its length and straightness preventing the cutter from descending into any hollows in the wood. The engineer's plane more resembles the turning-lathe, of which indeed it is but a modification, working up on the same principle, on flat surfaces. The tools or cutters in Clement's machine were similar to those used in the lathe, varying in like manner, but performing their work in right lines, the tool being stationary and the work moving under it, the tool only travelling when making lateral cuts. To save time two cutters were mounted, one to cut the work while going, the other while returning, both being so arranged and held as to be presented to the work in the firmest manner, and with the least possible friction. The bed of the machine, on which the work was laid, passed under the cutters on perfectly true rollers or wheels, lodged and held in their bearings as accurately as the best mandrill could be, and having set-screws acting against their ends totally preventing all end-motion. The machine was bedded on a massive and solid foundation of masonry in heavy blocks, the support at all points being so complete as effectually to destroy all tendency to vibration, with the object of securing full, round, and quiet cuts. The rollers on which the planing-machine travelled were so true, that Clement himself used to say of them, "If you were to put but a paper shaving under one of the rollers, it would at once stop all the rest." Nor was this any exaggeration - the entire mechanism, notwithstanding its great size, being as true and accurate as that of a watch.
By an ingenious adaptation of the apparatus, which will also be found described in the Society of Arts paper, the planing machine might be fitted with a lathe-bed, either to hold two centres, or a head with a suitable mandrill. When so fitted, the machine was enabled to do the work of a turning-lathe, though in a different way, cutting cylinders or cones in their longitudinal direction perfectly straight, as well as solids or prisms of any angle, either by the longitudinal or lateral motion of the cutter; whilst by making the work revolve, it might be turned as in any other lathe. This ingenious machine, as contrived by Mr. Clement, therefore represented a complete union of the turning-lathe with the planing machine and dividing engine, by which turning of the most complicated kind might readily be executed.
For ten years after it was set in motion, Clement's was the only machine of the sort available for planing large work; and being consequently very much in request, it was often kept going night and day, - the earnings by the planing machine alone during that time forming the principal income of its inventor. As it took in a piece of work six feet square, and as his charge for planing was three-halfpence the square inch, or eighteen shillings the square foot, he could thus earn by his machine alone some ten pounds for every day's work of twelve hours. We may add that since planing machines in various forms have become common in mechanical workshops, the cost of planing does not amount to more than three-halfpence the square foot.
The excellence of Mr. Clement's tools, and his well-known skill in designing and executing work requiring unusual accuracy and finish, led to his being employed by Mr. Babbage to make his celebrated Calculating or Difference Engine. The contrivance of a machine that should work out complicated sums in arithmetic with perfect precision, was, as may readily be imagined, one of the most difficult feats of the mechanical intellect. To do this was in an especial sense to stamp matter with the impress of mind, and render it subservient to the highest thinking faculty. Attempts had been made at an early period to perform arithmetical calculations by mechanical aids more rapidly and precisely than it was possible to do by the operations of the individual mind. The preparation of arithmetical tables of high numbers involved a vast deal of labour, and even with the greatest care errors were unavoidable and numerous. Thus in a multiplication-table prepared by a man so eminent as Dr. Hutton for the Board of Longitude, no fewer than forty errors were discovered in a single page taken at random. In the tables of the Nautical Almanac, where the greatest possible precision was desirable and necessary, more than five hundred errors were detected by one person; and the Tables of the Board of Longitude were found equally incorrect. But such errors were impossible to be avoided so long as the ordinary modes of calculating, transcribing, and printing continued in use.
The earliest and simplest form of calculating apparatus was that employed by the schoolboys of ancient Greece, called the Abacus; consisting of a smooth board with a narrow rim, on which they were taught to compute by means of progressive rows of pebbles, bits of bone or ivory, or pieces of silver coin, used as counters. The same board, strewn over with sand, was used for teaching the rudiments of writing and the principles of geometry. The Romans subsequently adopted the Abacus, dividing it by means of perpendicular lines or bars, and from the designation of calculus which they gave to each pebble or counter employed on the board, we have derived our English word to calculate. The same instrument continued to be employed during the middle ages, and the table used by the English Court of Exchequer was but a modified form of the Greek Abacus, the chequered lines across it giving the designation to the Court, which still survives. Tallies, from the French word tailler to cut, were another of the mechanical methods employed to record computations, though in a very rude way. Step by step improvements were made; the most important being that invented by Napier of Merchiston, the inventor of logarithms, commonly called Napier's bones, consisting of a number of rods divided into ten equal squares and numbered, so that the whole when placed together formed the common multiplication table. By these means various operations in multiplication and division were performed. Sir Samuel Morland, Gunter, and Lamb introduced other contrivances, applicable to trigonometry; Gunter's scale being still in common use. The calculating machines of Gersten and Pascal were of a different kind, working out arithmetical calculations by means of trains of wheels and other arrangements; and that contrived by Lord Stanhope for the purpose of verifying his calculations with respect to the National Debt was of like character. But none of these will bear for a moment to be compared with the machine designed by Mr. Babbage for performing arithmetical calculations and mathematical analyses, as well as for recording the calculations when made, thereby getting rid entirely of individual error in the operations of calculation, transcription, and printing.
The French government, in their desire to promote the extension of the decimal system, had ordered the construction of logarithmical tables of vast extent; but the great labour and expense involved in the undertaking prevented the design from being carried out. It was reserved for Mr. Babbage to develop the idea by means of a machine which he called the Difference Engine. This machine is of so complicated a character that it would be impossible for us to give any intelligible description of it in words . Although Dr. Lardner was unrivalled in the art of describing mechanism, he occupied twenty-five pages of the 'Edinburgh Review' (vol.59) in endeavouring to describe its action, and there were several features in it which he gave up as hopeless. Some parts of the apparatus and modes of action are indeed extraordinary and perhaps none more so than that for ensuring accuracy in the calculated results,--the machine actually correcting itself, and rubbing itself back into accuracy, when the disposition to err occurs, by the friction of the adjacent machinery! When an error is made, the wheels become locked and refuse to proceed; thus the machine must go rightly or not at all,--an arrangement as nearly resembling volition as anything that brass and steel are likely to accomplish.
This intricate subject was taken up by Mr. Babbage in 1821, when he undertook to superintend for the British government the construction of a machine for calculating and printing mathematical and astronomical tables. The model first constructed to illustrate the nature of his invention produced figures at the rate of 44 a minute. In 1823 the Royal Society was requested to report upon the invention, and after full inquiry the committee recommended it as one highly deserving of public encouragement. A sum of 1500L was then placed at Mr. Babbage's disposal by the Lords of the Treasury for the purpose of enabling him to perfect his invention. It was at this time that he engaged Mr. Clement as draughtsman and mechanic to embody his ideas in a working machine.
Numerous tools were expressly contrived by the latter for executing the several parts, and workmen were specially educated for the purpose of using them. Some idea of the elaborate character of the drawings may be formed from the fact that those required for the calculating machinery alone - not to mention the printing machinery, which was almost equally elaborate - covered not less than four hundred square feet of surface! The cost of executing the calculating machine was of course very great, and the progress of the work was necessarily slow. The consequence was that the government first became impatient, and then began to grumble at the expense. At the end of seven years the engineer's bills alone were found to amount to nearly 7200L, and Mr. Babbage's costs out of pocket to 7,000L more. In order to make more satisfactory progress, it was determined to remove the works to the neighbourhood of Mr. Babbage's own residence; but as Clement's claims for conducting the operations in the new premises were thought exorbitant, and as he himself considered that the work did not yield him the average profit of ordinary employment in his own trade, he eventually withdrew from the enterprise, taking with him the tools which he had constructed for executing the machine. The government also shortly after withdrew from it, and from that time the scheme was suspended, the Calculating Engine remaining a beautiful but unfinished fragment of a great work. Though originally intended to go as far as twenty figures, it was only completed to the extent of being capable of calculating to the depth of five figures, and two orders of differences; and only a small part of the proposed printing machinery was ever made. The engine was placed in the museum of King's College in 1843, enclosed in a glass case, until the year 1862, when it was removed for a time to the Great Exhibition, where it formed perhaps the most remarkable and beautifully executed piece of mechanism the combined result of intellectual and mechanical contrivance in the entire collection.
Clement was on various other occasions invited to undertake work requiring extra skill, which other mechanics were unwilling or unable to execute. He was thus always full of employment, never being under the necessity of canvassing for customers. He was almost constantly in his workshop, in which he took great pride. His dwelling was over the office in the yard, and it was with difficulty he could be induced to leave the premises. On one occasion Mr. Brunel of the Great Western Railway called upon him to ask if he could supply him with a superior steam-whistle for his locomotives, the whistles which they were using giving forth very little sound. Clement examined the specimen brought by Brunel, and pronounced it to be "mere tallow-chandler's work." He undertook to supply a proper article, and after his usual fashion he proceeded to contrive a machine or tool for the express purpose of making steam-whistles. They were made and supplied, and when mounted on the locomotive the effect was indeed "screaming." They were heard miles off, and Brunel, delighted, ordered a hundred. But when the bill came in, it was found that the charge made for them was very high - as much as 40L. the set. The company demurred at the price, Brunel declaring it to be six times more than the price they had before been paying. "That may be;" rejoined Clement, "but mine are more than six times better. You ordered a first-rate article, and you must be content to pay for it." The matter was referred to an arbitrator, who awarded the full sum claimed. Mr. Weld mentions a similar case of an order which Clement received from America to make a large screw of given dimensions "in the best possible manner," and he accordingly proceeded to make one with the greatest mathematical accuracy. But his bill amounted to some hundreds of pounds, which completely staggered the American, who did not calculate on having to pay more than 20L at the utmost for the screw. The matter was, however, referred to arbitrators, who gave their decision, as in the former case, in favour of the mechanic.
One of the last works which Clement executed as a matter of pleasure, was the building of an organ for his own use. It will be remembered that when working as a slater at Great Ashby, he had made flutes and clarinets, and now in his old age he determined to try his skill at making an organ - in his opinion the king of musical instruments. The building of it became his hobby, and his greatest delight was in superintending its progress. It cost him about two thousand pounds in labour alone, but he lived to finish it, and we have been informed that it was pronounced a very excellent instrument.
Clement was a heavy-browed man, without any polish of manner or speech; for to the last he continued to use his strong Westmoreland dialect. He was not educated in a literary sense; for he read but little, and could write with difficulty. He was eminently a mechanic, and had achieved his exquisite skill by observation, experience, and reflection. His head was a complete repertory of inventions, on which he was constantly drawing for the improvement of mechanical practice. Though he had never more than thirty workmen in his factory, they were all of the first class; and the example which Clement set before them of extreme carefulness and accuracy in execution rendered his shop one of the best schools of its time for the training of thoroughly accomplished mechanics. Mr. Clement died in 1844, in his sixty-fifth year; after which his works were carried on by Mr. Wilkinson, one of his nephews; and his planing machine still continues in useful work.