III.-On the singular Whirling Motion of a Watch-glass, without any apparent cause. Communicated to the EDITOR, by Mr. CHARLES WHEATSTONE, of Conduit Street.

MR. WHEATSTONE first saw this curious effect at the shop of a Lapidary, in Edinburgh, about a year and a half since; but it has only recently been recalled to his notice.

If a watch-glass be placed, with its convex side downwards, upon a plate of glass wetted with water, and the plate be inclined in a proper manner, it will soon begin to gyrate, or assume a circular movement, in addition to the sliding one, occasioned by inclining the glass plate; and this circular motion may be continued at pleasure, by so changing the inclination of the glass plate, as to cause the watch-glass to continually traverse along the edges or sides of the plate. Nay, by dexterous management, it may even be caused to run up hill, whilst the circular movement of the watch-glass continues, owing to its momentum, or vis inertia.

No satisfactory cause has as yet been given of this curious effect; the water is attracted in a circular form, underneath the centre of the watch-glass, and it is thought, exerts a tangential influence upon it, as it is carried along, and thus causes it to assume this circular motion.

The lapidary had formed the Scotch topaz into portions of solid spheres, and pretended that they must be necessarily employed to produce the above singular effects; a common watch-glass, however, is fully sufficient for the purpose.

IV.-On the Union of Mechanical Skill with the Highest Attainments in Science. By Dr. THOMAS P. JONES. (Continued from Vol. V. page 374.)

THE manufacture of pottery had remained in England in a comparative rude state, until Mr. Josias Wedgewood,

about sixty years ago, effected in it a complete revolution. The porcelain used by the opulent, was imported from France, to the great disadvantage of the English manufacturer. Wedgewood was the son of a potter in Staffordshire, and, from his early youth, was employed in his father's business. His education was very limited, and his patrimony small; but his mind was vigorous, and he soon manifested its superiority, by the improvements which he introduced.

By him was invented the Wedgewood, or Queen's-ware, which not only excluded the foreign manufacturer from the market, but also supplied a large quantity for exportation, and gave a new spur to trade, extending the business far beyond all former example. He made himself acquainted with chemistry, instituted a vast number of experiments, and discovered various materials, applicable to his business, forming many new species of earthen-ware, and porcelain, both useful and ornamental. As he acquired wealth, he liberally expended it for the promotion of the arts, particularly in their application to his own business. The figures on his cameos and intaglios, rivalled the productions of ancient Greece. The Portland vase, found in the tomb of the Emperor Severus, he imitated, with perfect success, in form, in colour, and in the grace and beauty of the figures with which it was enriched.

By his means the district which he inhabited became the centre of a vast population, and a place of great wealth. He lived highly esteemed for his moral and intellectual qualities, the associate of men distinguished for genius and science, and died universally regretted, in the year 1795.

Sir Richard Arkwright, the youngest of thirteen children, whose parents were in indigent circumstances, was originally a country barber; but although he enjoyed neither the advantages of fortune, or of education, nature had endowed him with a fine mechanical genius, and an untiring ardour in the pursuit of his objects; these qualities enabled him to rise above the numerous obstacles resulting from obscu

rity, from poverty, and from prejudice; procuring for him both rank and title, and enabling him to accumulate a princely fortune. His first recorded mechanical effort, was in the pursuit of the phantom, perpetual motion; a phantom which has misled a great number of men, possessing more mechanical genius than scientific information, and has sometimes beguiled those who had some claims to learning. Arkwright was induced to abandon his chimera, and he then turned his attention to the improvement of the machinery for the spinning of cotton. At this period, cotton was scarcely known in Great Britain as an article of commerce, whilst at the present day, it is in a commercial and manufacturing point of view, the most important; employing a large portion of her population in the various processes connected with it, and increasing the national wealth in an unexampled degree.

An individual, obscure, and apparently powerless, was destined, by his mechanical skill, to produce this mighty revolution; the business which he created, caused towns to be founded, where, otherwise, hamlets could scarcely have existed; and has given to the cultivator of the soil in our own (the United States), and many other countries, a most important article of produce, exhausting it but little, remunerating the labourer for his toil, and furnishing to every civilized country, innumerable articles of comfort and convenience. Before dismissing this eminent individual, we will remark, that the essential improvements made by him, remain with little or no alteration to the present day; these are, the ingenious mode of drawing out the cotton by means of rollers, and the beautiful process of delivering it from the cards in a continued fleece. The mechanical genius of Arkwright was not his only excellence, for after having carried his inventions into complete effect, he introduced into the manufactories in which he was concerned, a degree of order, cleanliness, and industry, altogether unexampled in any similar establishment. After speaking of the improvements made by Arkwright, in the manufacturing

of cotton, we are led, by a natural association, to the steamengine, as it came out of the hands of that scientific mechanic, Watt. At the time when Arkwright was bringing his machinery to perfection, Watt was a mathematical instrument-maker, in Glasgow. Having attended the lectures of Dr. Black, who was then professor of chemistry in that place, he had become acquainted with the doctrine of latent heat, as discovered and taught by that eminent individual. A working model of the atmospheric steam-engine was placed for repair in the hands of Watt; and he was led to remark the great waste of heat, in the condensation of the steam; a waste, the amount of which could be estimated only by one possessed of the scientific knowledge which he had derived from Dr. Black. To obviate this, required that singular skill which he displayed in the improvements which he introduced; producing economy in fuel, acquiring a vast accession of power, and rendering the motions of the machine so equable and manageable, as to adapt it perfectly to the purposes of the manufacturer; thus giving him a first mover, which he could use wherever a small quantity of water, and the requisite fuel, could be obtained. The steam-engine, therefore, contributed in an eminent degree to the success of the cotton manufacture, as well as to that of many others.

We shall have occasion to exhibit to you, at some other time, various proofs of the eminent skill of this philosophical mechanic, who, whilst he acquired the wealth which he so well deserved, gave to his country, and to the world, an instrument more powerful in its operation, and more general in its application, than any previously known. At the Chacewater mine, in Cornwall, there is a steam-engine erected, of 1010 horse power, and, of course, performing the labour which would require the employment of 3030 horses, supposing a horse to perform 8 hours constant labour, in every twenty-four. By this engine, a mine of 600 fathoms deep is kept dry. In numerous instances, mines which had been abandoned, in consequence of the

On Mr. Ross Winans's Improved American Carriage, &c. 23 impossibility, or the expence, of keeping them from water, are now worked with facility and profit; and the engine is applied to a variety of purposes, too numerous to detail. In the structure of the steam-engine, in its present improved state, we see the application of the principles of mechanical philosophy, in a number of beautiful and ingenious contrivances, which give to its motions the appearance of intellectual impulse; whilst a knowledge of the most recondite principles of chemical philosophy is displayed in the formation and arrangement of its several parts; exemplifying in a manner the most striking, that " knowledge is power," and proving the correctness of the observation, that this machine is "a present from philosophy to the arts."

(To be continued.)

V.-On Mr. Ross WINANS's Improved American Carriage for Rail Ways, and on Rail Ways. By J. L. SULLIVAN, Esq. Civil Engineer *.

THE public works of our country have received their impulse, and public opinion is daily attaching to them an increased value. The form first given to them had a direct relation to the more immediate and most important object, the domestic trade of the States to which they belong. But there is also another valuable object, not always sufficiently distinguished, namely, profit from transport. The agriculture of our extensive vallies, and the minerals abounding in their mountainous borders, demanded canals; and favourable ground, with abundance of water, recommended them. But revenue from transit commerce originating beyond the borders of the State, most active when the western waters are favourable to conveyance far into the country, the elevation of the intervening ground, and our climate, seem to prescribe rail-road communications.

• From the "Journal of the Franklin Institute." This carriage is patented in this country.