ple as well as ancient of arts. It is capable of demonstration, that this process, as generally conducted, is defective in several respects; and that, by substituting, in some cases, different materials, and in others, new modes of treating them, an essential saving might be realized, both of materials and time.

Another cause, which seriously interferes with success in the arts, is, the spurious quality of many of the substances employed. Without some means of detecting adulterations, the artist must often use substances deficient in the qualities required, and of course his results must be uncertain and unsatisfactory. Now, all these difficulties might be obviated, by a moderate acquaintance with chemistry and mechanical philosophy. These sciences suggest simple but yet certain means for testing the purity of substances, and they point out, at the same time, the shortest path to any required object. How wonderfully have the processes of bleaching, and tanning, and sugar-refining, been simplified and abridged, since they first attracted the attention of chemists! What immense improvements are constantly taking place, in the machinery of our large factories! Indeed, there is no department of life, in which a knowledge of science does not serve to simplify and improve our operations. "Though a man," says Lord Brougham, "be neither a mechanic nor a peasant, but only has a pot to boil, he is sure to learn, from science, lessons, which will enable him to cook his morsel better, save his fuel, and both vary his dish and improve it." The art of good and cheap cookery is intimately connected with the principles of chemical philosophy, and has received much, and will yet receive more, improvement, from their applications. It will be sufficient, under this head, to add two other illustrations, which we borrow from Mr. Herschel's admirable Discourse on the study of Natural Philosophy.'

"In the granite quarries, near Seringapatam, the most enormous blocks are separated from the solid rock, by the following neat and simple process. The work

man, having found a portion of the rock sufficiently extensive, and situated near the edge of the part already quarried, lays bare the upper surface, and marks on it a line, in the direction of the intended separation, along which a groove is cut, with a chisel, about a couple of inches in depth. Above this groove, a narrow line of fire is then kindled, and maintained till the rock below is thoroughly heated, immediately on which, a line of men and women, each provided with a pot full of cold water, suddenly sweep off the ashes, and pour the water into the heated groove, when the rock at once splits, with a clean fracture. Square blocks, of six feet in the side and upwards of eighty feet in length, are sometimes detached, by this method, or by another equally simple and efficacious, but not easily explained, without entering into particulars of mineralogical detail.”

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Hardly less simple and efficacious is the process, used in some parts of France, where millstones are made. When a mass of stone, sufficiently large, is found, it is cut into a cylinder, several feet high, and the question then arises, how to subdivide this into horizontal pieces, so as to make as many millstones. For this purpose, horizontal indentations, or grooves, are chiselled out, quite round the cylinder, at distances corresponding to the thickness intended to be given to the millstones, into which wedges of dried wood are driven. These are then wetted or exposed to the nightdew; and next morning, the different pieces are found separated from each other, by the expansion of the wood, consequent on its absorption of moisture; an irresistible natural power thus accomplishing, almost without any trouble and at no expense, an operation, which, from the peculiar hardness and texture of the stone, would otherwise be impracticable, but by the most powerful machinery, or the most persevering labor."

III. A third advantage, which the practical man derives from science, is, that it enables him to appreciate proposed improvements. The arts of the present age are characterized by nothing more striking, than by

their rapid and almost incredible progress.* Competition is so eager, and economy in operations so indispensable, that there is a perpetual tasking of the human intellect, to invent some cheaper, neater, or more rapid, combination. Hence it is, that one improvement is scarcely introduced, before another supersedes it. A thousand minds are engaged, perhaps at the same time, in the earnest pursuit of some contrivance, which will enable them to save a small fraction in the cost of production; and such contrivance, when once discovered, must either be adopted by all, or be the means of diverting to its fortunate proprietor the entire profits of the trade. It becomes, therefore, an object of the utmost importance to the mechanic and manufacturer, to be able, when a new method is proposed, to judge intelligently of its claims. He is to be equally on his guard against the skepticism which unhesitatingly condemns all new systems, and adheres, most pertinaciously, to whatever is old; and against that credulity which is ready to yield a blind and implicit assent to the promises of interested projectors. But nothing, evidently, can save him from one or other of these extremes, but that knowledge of principles, which will enable him to weigh the reasons for any proposed improvement, and to estimate its probable value. And as such knowledge is necessary, that he may appreciate improvements,† so is it necessary to assist him in

* The increasing powers of the steam-loom are shown in the following statement, furnished by a manufacturer.

"A very good hand-weaver, twenty-five or thirty years of age, will weave two pieces of 9-8ths shirting a week.

"In 1823, a steam-loom weaver, about fifteen years of age, attending two looms, could weave seven similar pieces in a week.

"In 1826, a steam-loom weaver, about fifteen years of age, attending two looms, could weave twelve similar pieces in a week; some, could weave fifteen pieces.

"In 1833, a steam-loom weaver, from fifteen to twenty years of age, assisted by a girl, about twelve years of age, attending four looms, could weave eighteen similar pieces in a week; some could weave twenty pieces."

† Dr. Ure states, in his Philosophy of Manufactures, that "prodigious sums are wastefully expended, every year, by manufacturers,

introducing and applying them. In the present state of the arts, and especially of important branches of manufacture, it is no longer safe, says Judge Story, to be ignorant. "It is not mere dexterity of hand, or mechanical adroitness or industry, that can secure to an individual a successful issue in his business. Without some science, to master improvements, as they occur, and to keep up, in a measure, with the spirit of the age, it will often happen that a mechanic, before he has reached the middle of life, will find himself superseded by those who, though much younger, have begun life under more favorable auspices.'

A fourth advantage which science gives the instructed over the uninstructed artisan is, that it enables him to become an improver of the art at which he works, and even a discoverer in the sciences connected with it. He is daily handling the tools and materials, with which new experiments are to be made, and daily witnessing the operations of Nature, whether in the motions and pressure of bodies, or in their chemical actions on each other. All opportunities of making experiments must be unimproved, all appearances must pass unobserved, if the artist has no knowledge of principles; but, with this knowledge, he, of all men, is most likely to strike out something new, which may be useful in art, or curious and interesting to science.* His practised eye and dexterous hand enable him to embrace the many opportunities afforded him for such improvements; and, if he labors in a large manufactory, both the motive and opportunity to make them are peculiarly great. The processes being on a large scale, and con

which would be saved by a more thorough acquaintance with the principles of science and art," which apply to their business; that "crafty projectors are perpetually pressing hazardous innovations upon their adoption," and that he has known not a few cases, where a complete system of good machines, capable of doing excellent work, had been capriciously turned out of a cotton factory, and replaced by another, of greater expense, but of less productive pow

ers."

* See Brougham's Discourse on the Advantages of Science.

sequently very expensive, it becomes the more important to devise means of saving material and labor, while the very magnitude of these processes often brings out facts and principles which, in ordinary operations, would have remained imperceptible. But the importance, in this respect, of scientific attainments will become more apparent, if we consider the following qualifications, which are absolutely necessary to enable any one to become the author of important improvements

in the arts.

I. He must know enough of the laws of Nature, not to attempt impossibilities. Nature itself has placed insuperable difficulties in the way of many of the objects which have exercised the ingenuity, and wasted the property and lives, of ardent but ignorant inquirers. Who, for example, that were acquainted with the laws of chemical composition, or with the physical constitution of man, would have spent their lives and fortunes, as the alchymists did, in the pursuit of the philosopher's stone, or the elixir of life? Who, that understands the laws of motion and gravitation, would ever hope to invent perpetual motion, or a machine to multiply force and velocity at the same time? How many monuments of the ignorance of their projectors do we find in the models of a patent-office, and indeed in many of the undertakings of common life! One man attempts what the laws of Nature have peremptorily forbidden. Another attempts an object, practicable in itself, but by means totally inadequate or inappropriate. This one opens a mine, establishes machinery, and expends a hundred thousand dollars, to discover,—what a geologist would have told him at the outset,-that no ore can be obtained. Another man proposes to increase the heat of his furnace, by forcing in steam instead of air, and the result is, that the fire, instead of being increased, is blown out; a result which a slight knowledge of chemistry would have prepared him to expect. A third projector prepares a vessel* for sub

* See page 74.