bling puppet were revived in the chronometer, which now conducts navies through the ocean; and the shapeless wheel which directed the hand of the drawing automaton, has served in the present age to guide the movements of the tambouring engine. Those mechani cal wonders which in one century enriched only the conjurer who used them, contributed in another to augment the wealth of the nation; and those automatic toys which once amused the vulgar, are now employed in extending the power and promoting the civi lization of our species. In whatever way, indeed, the power of genius may invent or combine, and to whatever low or even ludi crous purposes that invention or combination may be originally applied, society receives a gift which it can never lose; and though the value of the seed may not be at once recognised, and though it may lie long unproductive in the ungenial till of human knowledge, it will some time or other evolve its germ, and yield to mankind its natural and abundant harvest.

Duncan's tambouring machine.—The tambouring of muslins, o the art of producing upon them ornamental flowers and figures, has been long known and practised in Britain, as well as in other counries; but it was not long before the year 1790 that it became an object of general manufacture in the west of Scotland, where it was chiefly carried on. At first it was under the direction of foreigners; but their aid was not long necessary, and it speedily extended to such a degree as to occupy either wholly or partially more than 20,000 females. Many of these laborers lived in the neighborhood of Glasgow, which was the chief seat of the manufacture, but others were scattered through every part of Scotland, and supplied by agents with work and money. In Glasgow, a tambourer of ordinary skill could not in general earn more than five or six shillings a week by constant application; but to a laboring artisan, who had several daughters, even these low wages formed a source of great wealth. At the age of five years, a child capable of handling a needle was devoted to tambouring, even though it could not earn more than a shilling or two in a week; and the consequence of this was, that female children were taken from school, and rendered totally unfit for any social or domestic duty. The tambouring population was therefore of the worst kind, and it must have been regarded as a blessing rather than as a calamity, when the work which they performed was intrusted to regular machinery.

Mr. John Duncan of Glasgow, the inventor of the tambouring machinery, was one of those unfortunate individuals who benefit their species without benefiting themselves, and who died in the meridian of life the victim of poverty and of national ingratitude. He conceived the idea of bringing into action a great number of

needles at the same time, in order to shorten the process by manual labor, but he at first was perplexed about the diversification of the pattern. This difficulty, however, he soon surmounted by employing two forces at right angles to each other, which gave him a new force in the direction of the diagonal of the parallelogram, whose sides were formed hy the original forces. His first machine was very imperfect; but after two years' study he formed a company, at whose expense six improved machines were put in action, and who secured the invention by a patent. At this time the idea of rendering the machine automatic had scarcely occurred to him; but he afterward succeeded in accomplishing this great object, and the tambouring machines were placed under the surveillance of a steam-engine. Another patent was taken for these improvements. The reader who desires to have a minute account of these improvements, and of the various parts of the machinery, will be amply gratified by perusing the inventor's own account of the machinery in the article CHAIN WORK in the Edinburgh Encyclopedia. At present it will be sufficient to state, that the muslin to be tamboured was suspended vertically in a frame which was capable of being moved both in a vertical and a horizontal direction. Sixty or more needles lying horizontally occupied a frame in front of the muslin web. Each of these working needles, as they are called, was attended by a feeding-needle, which, by a circular motion round the working-needle, lodged upon the stem of the latter the loop of the thread. The sixty needles then penetrated the web, and in order that they might return again without injuring the fabric, the barb or eye of the needle, which resembled the barb of a fishinghook, was shut by a slider. The muslin web then took a new position by means of the machinery that gave it its horizontal and vertical motion, so that the sixty needles penetrated it at their next movement at another point of the figure or flower. This operation went on till sixty flowers were completed. The web was then slightly wound up, that the needles might be opposite that part of it on which they were to work another row of flowers.

The flowers were generally at an inch distance, and the rows were placed so that the flowers formed what are called diamonds. There were seventy-two rows of flowers in a yard, so that in every square yard there were nearly four thousand flowers, and in every piece of ten yards long forty thousand. The number of loops or stitches in a flower varied with the pattern, but on an average there were about thirty. Hence the number of stitches in a yard were one hundred and twenty thousand, and the number in a piece is one million two hundred thousand. The average work done in a week by one machine was fifteen yards, or sixty thousand

flowers, or one million eight hundred thousand stitches; and by comparing this with the work done by one person with the hand, it appears that the machine enabled one person to do the work of twenty-four persons.

Watt's statue turning machinery.—One of the most curious and important applications of machinery to the arts which has been suggested in modern times was made by the late Mr. Watt, in the construction of a machine for copying or reducing statues and sculpture of all kinds. The art of multiplying busts and statues, by casts in plaster of Paris, has been the means of diffusing a knowledge of this branch of the fine arts; but from the fragile nature of the material, the copies thus produced were unfit for exposure to the weather, and therefore ill calculated for ornamenting public buildings, or for perpetuating the memory of public achievements. A machine, therefore, which is capable of multiplying the labors of the sculptor in the durable materials of marble or of brass was a desideratum of the highest va.ue, and one which could have been expected only from a genius of the first order. During many years Mr. Watt carried on his labors in secret, and he concealed even his intention of constructing such a machine. After he had made considerable progress in its execution, and had thought of securing his invention by a patent, he learned that an ingenious individual in his own neighborhood had been long occupied in the same pursuit; and Mr. Watt informed me that he had every reason to believe that this gentleman was entirely ignorant of his labors. A proposal was then made that the two inventors should combine their talents, and secure the privilege by a joint patent; but Mr. Watt had experienced so frequently the fatal operation of our patent laws, that he saw many difficulties in the way of such an arrangement, and he was unwilling, at his advanced age, to embark in a project so extensive, and which seemed to require for its successful prosecution all the ardor and ambition of a youthful mind. The scheme was therefore abandoned; and such is the unfortunate operation of our patent laws, that the circumstance of two individuals having made the same invention has prevented both from bringing it to perfection, and conferring a great practical benefit upon their species. The machine which Mr. Watt had constructed had actually executed some excellent pieces of work. I have seen in his house at Heathfield copies of basso-relievos, and complete statues of a small size; and some of his friends have in their possession other specimens of its performance.

Babbage's calculating machine.-Of all the machines which have been constructed in modern times, the calculating machine

is doubtless the most extraordinary. Pieces of mechanism for performing particular arithmetical operations have been long ago constructed, but these bear no comparison either in ingenuity or in magnitude to the grand design conceived and nearly executed by Mr. Babbage. Great as the power of mechanism is known to be, yet we venture to say that many of the most intelligent of our readers will scarcely admit it to be possible that astronomical and navigation tables can be accurately computed by machinery; that the machine can itself correct the errors which it may commit; and that the results of its calculations when absolutely free from error, can be printed off, without the aid of human hands, or the operation of human intelligence. All this, however, Mr. Babbage's machine can do; and as I have had the ad. vantage of seeing it actually calculate, and of studying its construction with Mr. Babbage himself, I am able to make the above statement on personal observation. The calculating machine now constructing under the superintendence of the inventor has been executed at the expense of the British government, and is of course their property. It consists essentially of two parts—a calculating part and a printing part, both of which are necessary to the fulfil. ment of Mr. Babbage's views, for the whole advantage would be lost if the computations made by the machine were copied by human hands and transferred to types by the common process. The greater part of the calculating machinery is already constructed, and exhibits workmanship of such extraordinary skill and beauty that nothing approaching to it has been witnessed. In order to execute it, particularly those parts of the apparatus which are dissimilar to any used in ordinary mechanical construc. tions, tools and machinery of great expense and complexity have been invented and constructed; and in many instances contrivances of singular ingenuity have been resorted to, which cannot fail to prove extensively useful in various branches of the mechanical arts.

The drawings of this machinery, which form a large part of the work, and on which all the contrivance has been bestowed, and all the alterations made, cover upwards of four hundred square feet of surface, and are executed with extraordinary care and precision.

In so complex a piece of mechanism, in which interrupted motions are propagated simultaneously along a great variety of trains of mechanism, it might have been supposed that obstructions would arise, or even incompatibilities occur, from the impracticability of foreseeing all the possible combinations of the parts; but this doubt has been entirely removed, by the constan*

eployment of a system of mechanical notation invented by Mr. Babbage, which places distinctly in view at every instant the progress of motion through all the parts of this or any other machine; and by writing down in tables the times required for all the movements, this method renders it easy to avoid all risk of two opposite actions arriving at the same instant at any part of the engine.

In the printing part of the machine less progress has been made in the actual execution than in the calculating part. The cause of this is the greater difficulty of its contrivance, not for transferring the computations from the calculating part to the copper or other plate destined to receive it, but for giving to the plate itself that number and variety of movements which the forms adopted in printed tables may call for in practice.

The practical object of the calculating engine is to compute and print a great variety and extent of astronomical and navigation tables, which could not be done without enormous intellectual and manual labor, and which, even if executed by such labor, could not be calculated with the requisite accuracy. Mathematicians, astronomers, and navigators do not require to be informed of the real value of such tables; but it may be proper to state, for the information of others, that seventeen large folio volumes of logarithmic tables alone were calculated at an enormous expense by the French government; and that the British government regarded these tables to be of such national value, that they proposed to the French Board of Longitude to print an abridgmen of them at the joint expense of the two nations, and offered to advance £5000 for that purpose. Besides logarithmic tables, Mr. Babbage's machine will calculate tables of the powers and products of numbers, and all astronomical tables for determining the positions of the sun, moon, and planets; and the same mechanical principles have enabled him to integrate innumerable equations of finite differences, that is, when the equation of differences is given, he can, by setting an engine, produce at the end of a given time any distant term which may be required, or any succession of terms commencing at a distant point.

Besides the cheapness and celerity with which this machine will perform its work, the absolute accuracy of the printed results deserves especial notice. By peculiar contrivances, any small error produced by accidental dust or by any slight inaccuracy in one of the wheels, is corrected as soon as it is transmitted to the next, and this is done in such a manner as effectually to prevent any accumulation of small errors from producing an erroneous figure in the result.