opolize any of the advantages resulting from great undertakings, or that would, in any degree, tend to defraud them of their just portions of these advantages.

In the application of scientific principles to researches of this nature, and the advantages to be ultimately derived from machines, whether propelled by animal, by steam, or by any other power; whether on railway, ordinary roads, canals or other water courses; the subject for investigation, as in all other departments of science, is the accurate determination of that relation which must always exist between an effect, and the cause producing it; or in the present inquiry, the relation existing between the mass, of whatever nature it may be, transported over a certain distance in a given time, and the cause producing that effect. This relation being, however, variable almost without limit, it becomes important to inquire what that cause may be, among the variety that may present themselves, which will give the most general, useful and practical result.

The value of time, being an important item in this investigation, common sense will always prefer the most expeditious mode of conveyance, when this choice can be made. For to economize time is in reality the main object of all useful industry and invention; and whatever machine or contrivance produces a certain effect in the shortest time, the expense and all other advantages being the same, must always be considered the most useful and important. If again we suppose the expense alone to vary, then that power, or mode of conveyance, which would produce the same effect in the same time, and at the least expense, would be the most advantageous; or if the time and expense be the same, and the risk or danger from whatever cause, greater in one mode of conveyance than another, that which is attended with the least risk or danger, ought evidently to be preferred. These general and evident principles should never be lost sight of in the present inquiry. Various circumstances may, however, modify their results, and these circumstances, no less than the general principles themselves, should be minutely and accurately attended to.

The value of the articles, or goods transported, with the quickness of the demand for them, is another essential item in this investigation; for in this respect, their value is nothing during the time of transportation. The more valuable, therefore, the articles, and the greater the demand for them, the more important it becomes to diminish the time.

The circumstances of the persons must also influence the mode of transportation. For admitting time equally at the disposal of

all, it does not become equally valuable for all. The man who travels for pleasure or amusement sets little value comparatively on time. It generally passes on without loss or profit to him; but to the man of business, who travels from the necessity of the case, and to whom time is precious, the increased rapidity of his journey is so much gained, and for which he can afford a proportional price. Whatever, in this point of view, applies to one man, must evidently apply to a whole community; so that the more active and industrious a nation is, the more time becomes precious. It may be also observed, that the more distant the individuals are, the more important becomes a speedy communication; for unless this speedy intercourse be established, the value of time may be such to the individuals, as to prohibit any intercourse whatever. Hence the more numerous and expeditious the means of transportation, the more certain are the facilities, and evident, the index of the prosperity of that country.

It is science alone, however, that can estimate with any degree of precision, the results of the combined actions of these various causes, and no safer or more certain mode can possibly be adopted than the one pursued by the great Newton, in his researches and discoveries of the laws of nature. He first carefully investigated different possible laws or elementary principles, on various hypotheses, and then adapted the proper law to the particular circumstances. It is evident that any wrong application of established laws or principles of science-such as drawing general conclusions from particular premises, or any conclusions which the premises do not warrant―must entirely defeat the object of the inquirer, and become a source more prolific in producing and propagating error, than absolute ignorance itself.

In making these estimates accurately, very little reliance can generally be placed on precedents; for, within the circle of our own limited observation, we could easily point out, in many of our internal improvements, were it not rather invidious, instances, where some hundred thousand dollars have been expended on works of comparatively little utility, and which are now suffered to go to destruction. Many of these works, even of real utility, might be often constructed, at much less expense, if judiciously managed. These defects being occasionally discovered, may be one of those causes producing the indifference which is evidently exhibited, at present, to undertakings of this nature, though of immense importance, probably as much so, as any thing connected with the prosperity of a country; pro

vided they do not interfere with other paramount state interests and rights. Instances have even occurred where instead of advantages, very extensive and serious injury have resulted from those ill advised and ill concerted undertakings. In almost all these instances, a knowledge of the most elementary principles of science would have pointed out the absurdity of-and prevented many of the injuries consequent on these undertakings. The application of the simple relation between the strength and stress, or pressure, of the materials used; the laws of the vibration, in some instances, of those materials; the simple hydrostatic principle of the pressure of fluids being as their depth, or even of the well known fact of the deposition of substances by water when its velocity is diminished, would have often prevented a failure. Among innumerable examples, we shall select but the few following illustrations of the preceding observation. The giving way of the arched or vaulted floor, in the Representative hall of the capitol at Washington; the falling of the Potomac bridge near the falls above Georgetown, in the District of Columbia; the fall of almost all the iron bridges first erected in England, owing to the same cause, their vibration; the failure of the celebrated causeway to Mason's Island opposite the same Georgetown, erected at immense expense with a view of deepening the channel there. This last has converted a navigation, where a sufficient depth of water existed to admit a seventy-four above Georgetown, to one with scarcely a depth of water sufficient to admit an oyster boat.* The history and developement of even these few instances of failure would encroach too much on the limits of this article. We may say with the poet, "Longa est injuria, longæ ambages," but the reviewer who should say "summa sequar fastigia rerum," would find it rather difficult with the aid even of Dedalus and his thread, to pursue the mazes of this labyrinth, particularly in our extensive public works.

It is with some reluctance that we add one more example to those already pointed out. We allude to the immense dam over the Broad-river, at Columbia, South-Carolina, constructed principally with such perishable materials as pine-logs. Though far from being permanent, it has completely ob

The failure in this instance was evidently owing to the deposition of sediment below the Island, where the channel, stopped by the causeway, meeting the other, continued its velocity and prevented this deposition. This principle is exemplified every day in the numerous sand bars and islands, formed in our rivers, particularly at their mouth; having lost, in their discharge into the ocean, the velocity retained while confined in their respective channels, or being counteracted by tides. Where this is not the case, the islands or sand bars are not formed.

structed the navigation of the river, and nearly destroyed its valuable shad-fishery, by impeding the further progress of the fish. As the canal, however, to which this serves as a feeder, is of immense importance to the trade of Columbia, and, as we are informed, the only one among our public works, which pays for itself, this dam should be very soon repaired, else even this work will become useless. There is near Bullsluice, in the Broad-river, a useless lock, with a temporary dam, which it appears has already cost the State upwards of $30,000. Probably for a sum less than this, the water could have been conducted in the first instance, from Bull-sluice to the Columbia Canal, affording, at all times, a sufficient supply of water, and enabling it to pay more than double what it pays at present. A company, we understand, would immediately undertake this work at their private expense, if the privilege were granted to them. At all events, if the trade of Columbia be worth preserving, something must be done and that soon. We see other towns and states making immense exertions, and we shall see them succeed in proportion as their exertions are persevered in, and judiciously conducted. We hope this will be the case with our Rail-road from Charleston, and its branches, for they will not only promote the interests of their stockholders, but the State will thus lay a strong foundation for preserving its rights, as well as its sovereignty. When a country makes use of all its resources untrammelled, then its prosperity will advance in proportion.

A late writer, we believe Sir H. Davy, remarks, (we quote, however, the substance of his remarks from memory) that it is in science as in war, every principle which is established is a victory which is gained, and which enables us to push our conquests still further, and to enlarge more and more the empire of reason and our dominion over nature. Still the parsimonious will calculate the dollars and cents that are expended in its advancement, but scarcely ever consider the benefits they receive from its cultivation, and the important truths which it unfolds. They collect its fruits as they too often do those presented by the munificence of a supreme being, while scarcely bestowing a thought on the source whence they are derived.

There is not a single principle or truth pointed out in science, or a fact that is well established in these investigations, that when made known does not become a legacy to posterity. "For science, (says Sir H. Davy) like that nature to which 'it belongs, is neither limited to time nor space, it is of no 'country, it belongs to the world."

"Who (says Dr. Johnson in the Rambler,) when he saw 'the sand or ashes, by a casual intenseness of heat, melted into 'a metalline form, rugged with excrescences and clouded with 'impurities, would have imagined that in this shapeless lump 'lay concealed so many conveniencies of life, as would, in 'time, constitute a great part of the happiness of the world? Yet by some such fortuitous liquefaction, was mankind taught 'to procure a body, at once in a high degree solid and trans'parent, which might admit the light of the sun, and exclude the violence of the wind, which might extend the sight of the 'philosopher to new ranges of existence, and charm him at ' one time with the unbounded extent of the material creation, and at another with the endless subordination of animal life; and what is yet of more importance, might supply the decays 'of nature, and succour old age with subsidiary sight. Thus 'was the first artificer in glass employed, though without his 'own knowledge or expectation. He was facilitating or prolonging the enjoyment of light, enlarging the avenues of science, and conferring the highest and most lasting pleasures; 'he was enabling the student to contemplate nature, and beau'ty to behold herself.'

We could not resist the temptation of inserting this beautiful description of the effects of the discovery of glass, although aware that nature, independent of art, had prepared a material in the rock or quartz crystal, far superior to glass, in supplying the wants of old age, or in assisting the student, or even beauty herself.

But of what importance could any of these materials be, whether produced by accident, by art, or by nature, were not the light of science to point out their utility, and extend their application. Without the science and skill of the optician, of what use could the Doctor's rugged, shapeless, transparent lump of glass become, or even the beautiful crystal. It is, then, no less important that discoveries should be made, than that, when they are made, they should become known and appreciated, and their utility pointed out and elucidated by science.

It is unfortunately, however, the fate of the sciences that they are studied comparatively by very few; generally speaking, we find that those who need them most are the most ignorant of them. The mechanic, the artist, the engineer, undertake the most expensive and important works, with scarcely the rudiments of those branches of knowledge, which alone can render them skilful, and ensure success. The navigator often commits himself, with his frail vessel, to the ocean, when even the allimportant knowledge of determining his latitude or longitude,