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ed, for producing the different results of mechanics, but may be all reduced to these simple elements.

By means of these, the muscular power of man is enabled greatly to increase its effect; that is, a man by his own strength can now accomplish labor which he could not accomplish without them. Though these instruments give no new strength, yet they greatly increase the effectiveness of that which already exists; and hence, their invention marks an important era in the progress of civilization. also to be remarked, that their origin, in point of time, is far in advance of the discovery of the creative agents.

Archimedes had made great progress in the discovery and application of these modifying powers, when the use of creative agents was almost unknown.

The triumph of human skill is, however, achieved, when these two forms of natural agency are combined in a single machine. By the one we generate power, to what extent soever we choose; and by the other we modify it in any form, to give it any application, and direct it to any purpose, that our convenience may require. It is in this manner, that man renders all the various powers of nature tributary to himself. He can thus create, and use as he pleases, as great a power as he desires. He devolves the labor on nature, and he has only to fabricate the instruments, and give them their direction. He is successful just in proportion as he does this; since nature always works with undeviating accuracy, with unerring skill, with indefatigable perseverance; and she always works for nothing.

It may be useful to specify some of the results accomplished by the various instruments, which man employs for modifying that momentum which is exerted by the first class of natural agents.

1. We are thus enabled to change the direction of the power. Thus, in the cylinder of the steam engine, the momentum is created either in perpendicular or horizontal strokes. This, being by means of an arm and a crank changed into a circular motion, moves the paddle-wheels of a steamboat. Thus, also, in the machinery for moving a trip-hammer, a circular is changed into a perpendicular motion, by the striking of the cogs of a wheel upon the short arm of a lever, while the hammer is attached to the other arm.

2. We exchange power for velocity. This is done in all spinning machinery. By water or by steam, we cause a large wheel to revolve ten, twenty, or thirty times in a minute, and with a power equal to that which could be produced by fifty or one hundred horses. In spinning, however, we need small power, but great velocity. Hence, by the combination of various large and small wheels, we produce a velocity, in a thousand spindles, equal to many thousand revolutions in a minute. The whole of this fifty or one hundred horse power, is thus spread over a large manufactory, and adapted, by various contrivances, to every degree of velocity, and every form of motion that may be required.

3. We are thus enabled to exert forces too great for animate power. By water power, or by steam, we can generate as great a force as we please; and we have only to combine with it the

proper adjustments, in order to exert upon any point any momentum which we desire. The power required to roll and hammer iron, or copper, to propel steamboats, to forge anchors, and that used in several other of the arts, is greater than could be exerted by any animate force with which we are acquainted, unless it were exerted by means of some combination of the mechanical forces.

4. We are thus also enabled to execute operations too delicate for human touch. Very delicate operations, soon weary the nervous system by the excessive attention which they of necessity require. Thus, in order to spin the finest thread on a spinning wheel, there must be great accuracy, both in the velocity of the wheel, and in the muscular power exerted

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in drawing out the thread. This requires an effort of attention, which the human system cannot long maintain, and, of course, the thread will frequently be uneven. But by means of machinery, both of these operations may be adjusted with mathematical accuracy; and as machines have no nerves, they will be perfectly faithful to that adjustment. Thus we invariably see that the most delicate fabrics are those that are wrought by natural agents. Hence machinery is necessarily used in the manufacture of such articles as require for their formation identity of result, such as screws, types, &c.

5. By means of machinery, we are enabled to accumulate power.

We thus exchange a continuous and small force, for a sudden and violent one. Such is the case with the pile-driver, and the common beetle or mallet, when used in combination with the wedge.

6. By the same means we are enabled to exchange a short and irregular effort for a continuous and regular movement, or to spread the action of a short, over a long period of time. This is done in clocks, watches, and other similar machinery. Here we spread the action of a minute, over a day, or a week, and with almost mathematical accuracy,

In consequence of the above mentioned application of machinery, various other advantages are realised in production. For instance; there is frequently a great saving of material, as in the change from making boards with the adze, to that of making them with the saw; and again the labor of natural agents is so much cheaper, that many articles, which would otherwise have been worthless, are now deserving of attention, as they may now be profitably endowed with some form of value.

I close these remarks, upon the use of natural agents, with an extract, very graphically describing the power of the steam engine, which has commonly been ascribed to Francis Jeffrey, Esquire, of Edinburgh:

“It (the steam engine) has become a thing, stupendous alike for its force and its flexibility; for the prodigious power which it can exert; and the ease, precision and ductility with which it can be varied, distributed and applied. The trunk of an elephant, that can pick up a pin or rend an oak, is as nothing to it. It can engrave a seal, and crush masses of obdurate metal before it; draw out, without breaking, a thread as fine as a gossamer; and lift up a ship of war, like a bauble in the air. It can embroider muslin, and forge anchors; cut steele into ribands, and impel loaded vessels against the fury of the winds and waves.

"It would be difficult to estimate the value of the benefits which these inventions have conferred upon the country. There is no branch of industry that has not been indebted to them, and in all the most material, they have not only widened most magnificently the field of its exertions, but multiplied, a thousand fold, the amount of its productions. It is our improved steam engine, that has fought the battles of Europe, and exalted and sustained, through the late tremendous contest, the political greatness of our land. It is the same great power, which enables us to pay our national debt, and to maintain the arduous struggle in which we are still engaged, with the skill and capital of countries less oppressed with taxation.

“But these are poor and narrow views of its importance. It has increased, indefinitely, the mass of human comforts and enjoyments, and rendered cheap and accessible, all over the world, the materials of wealth and prosperity. It has armed the feeble hand of man, in short, with a power to which no limits can be assigned; completed the dominion of mind over the most refractory qualities of matter; and laid a sure foundation for alĩ those future miracles of mechanical power, which are to aid and reward the labors of after generations."





We have shown that the productiveness of human industry may be greatly increased by the discovery of the qualities and relations of things, and by the invention of instruments, by which those qualities may be applied and modified. In this manner, the power of man receives an almost incalculable augmentation. But this is not all. It is found that the result of human effort may be still farther very greatly increased. Thus: supposing the agents of nature, and also their mode of application, to be known, and that a given number of men are about to perform an operation, they may make such arrangements among themselves, as will, in a given time, and with a given expenditure of labor, enable them to accomplish a vastly greater result than could be accomplished without such arrangements. The mode, in which this is effected, is by division of labor.

Division of labor is always, to some degree, employed where different individuals are engaged in the different branches of human industry. Thus, labor is divided when different persons employ themselves in the several departments of discovery, application, and operation. Labor is still further divided, when those employed in these great departments, are separated into distinct classes, each class devoting itself to the accomplishment of one particular object. Thus, one man investigates the laws of mechanics; another, those of astronomy; and a third, those of vegetation. One man is devoted to the profession of the law; and another, to that of medicine; while each separate trade is employed in the creation of a particular product. By all these divisions, it is manifest that the result of the whole is greatly increased. It is only the savage, that combines in his own per

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