time of the original experiment, a velocity of four miles per hour, and this he increased to five, by slight modifications in the working of the engine. A farther increase to six miles per hour, was made in the boats which he placed upon the Hudson. In the vessel intended for the navigation of the Sound, he resolved to attempt a speed of nine miles per hour.

Confirmed in his hopes by the performance of this vessel, he commenced the construction of one, which, under some inducements held out by the Emperor of Russia, he proposed to send to St. Petersburgh. His death intervened before this vessel was finished, and want of funds compelled his associates to alter the destination of the vessel, and thus, instead of visiting Russia under the name of "the Emperor Alexander," she was placed on Long Island Sound, under the name of "the Connecticut."

The great and surpassing merit of Fulton consisted not so much in absolute originality, as in the skill with which he availed himself of all the theoretic knowledge of the day, and applied it to practical purposes. He had, upon the principles then received, formed for himself rules by which he was enabled to combine an engine of known power with a vessel of given dimensions, in such a manner, as to obtain the velocity he desired. And in no instance did he fail of success. But the received theories were founded upon limited experience, and the generalization was extended beyond the limit which the facts warranted. The rules which he had investigated, although true in all the instances to which he attempted to apply them, cease to be applicable to higher velocities. It is fortunate that they are so; for Fulton, in strict conformity with all which was then known of the laws of fluid resistance, had come to the conclusion that nine nautical miles was the highest degree of speed that it would ever be expedient to give to a steamboat. All speed beyond that limit, he inferred, would be attended with a cost which would far exceed the probable advantage; nay, that a very small increase of velocity beyond nine knots per hour, would require such increase in the dimensions of engine and boiler, together with such enormous consumption of fuel, that no vessel would be able to carry them.

In this respect, Fulton may be likened to Columbus, for, as the latter, misled by the imperfect knowledge of his age, died without knowing that he had discovered a new world, and without the means of anticipating the vast results which were to flow from his brilliant enterprize; so the former, trusting to the scientific theories of his cotemporaries, believed that he had reached

the utmost limit of his invention, and died without being aware how far space and time were to be vanquished by the followers in his footsteps. Nor were they unlike in other respects; both were treated as visionaries until the success of their projects was established, and yet, when this was the case, the very simplicity of the principles by which they had been directed, was made use of as an argument to rob them not only of the fame, but of the pecuniary reward, to which they were entitled. To both, an impartial posterity is now awarding the meed of praise which, when living, was denied them.

Fulton was not alone in this error. Although it is now well known in the United States, by positive experiment, that the received theory is in fault at the higher velocities, it is still gravely stated in scientific works, that the power of an engine to propel a given boat, must be increased in as high a ratio as the cube of the velocity; and that to perform a given distance at an increased speed, will demand an expenditure of fuel proportioned to the square of the velocity. Nor do many of the engineers of Europe, even up to the present day, venture to question this result; in compliance with which, no attempt seems to have been made by them, until very recently, to obtain velocities greater than nine nautical miles per hour.

Nothing, in fact, can be less perfect than the theories which have been laid down by men pretending to science, nay, really possessing both mathematical and physical knowledge, in relation not only to the resistance of fluids, and the motion of vessels in them, but even as respects the more simple case of the action of the steam engine itself. It is foreign to our present object to show in what manner the received theories have been found to differ from the results of observation in our American steamboats. It is sufficient for our purpose to state, that a comparison of the rate of motion of numerous vessels, has established conclusively, that so far from their being a constant relation between the velocity of a vessel and that of the paddles by which she is propelled, the difference between these two velocities is a constant quantity. It would appear to follow from this, that every increase in the velocity of the wheels would be attended with an equal increase in the velocity of the vessel, and that the expenditure of fuel will increase more rapidly in the lower than in the higher velocities of a steamboat.

Up to the time that the exclusive grant to Fulton was declared to be unconstitutional by the Supreme Court of the United States, the celerity of the vessels belonging to the privileged

company did not exceed eight miles an hour, through the water, and the average passages to Albany were eighteen hours. On the Delaware on the other hand, an active competition was frequently going on, between companies contending for a preference in the conveyance of passengers. In these contests, the son of Stevens of Hoboken, who had been carefully trained as an engineer by his father, was gradually forming himself for the struggle which was about to open on the Hudson. No sooner had the navigation of the latter river been laid open than numerous companies were formed to avail themselves of the opening. Vessels resembling in their speed and structure those of Fulton, but of inferior cost, lighter and less expensive to maintain, were placed in opposition to those of the privileged company. An attempt to convey passengers in tow-boats followed, and were it possible, by superiority of comfort and convenience, to counteract the innate desire to be first in a contest of speed, these must have been successful. It was, however, speedily seen, that the great object to be sought was that of making the passage from Albany to New York, between sunrise and sunset. The first vessel by which this feat was attempted was the Sun. This vessel was furnished with an engine on the principle of Wolf, in which, by means of two cylinders, the properties of the high pressure and condensing engine were united; the steam acting in the first cylinder by its absolute tension, in the second by its expansive force. The Sun, however, failed in accomplishing the object, and her passages were usually prolonged into the night.

At this moment Robert L. Stevens placed on the Hudson River a vessel, which, under the name of the New Philadelphia, had been constructed at Hoboken for the navigation of the Delaware. The attempt in which the Sun had failed was readily accomplished, and the practicability of making the passage to Albany by daylight established. Stevens, however, was not permitted to enjoy the exclusive privilege of the rapid passage he had shown to be practicable. Two other vessels, the Independence and the Victory, were placed in competition with him; and the New Philadelphia was in her turn overcome in the trial of speed. This defeat was soon converted into a triumph, for the same vessel was so modified as again to possess the superiority. For this purpose the cylinder of the engine was increased in length, by the addition of a separate piece; and to insure a supply of steam for this increased capacity, the flow of vapor from the boiler was cut off at half-stroke, and the steam was thus made to cut expansively. His opponents were not slow in adopt

ing the same methods, and each in their turn appeared to have gained the advantage. In the meantime, however, Stevens was busily engaged in building the North America, a vessel which for a long time remained unrivalled in speed, except, perhaps, by some occasional performances of the New Philadelphia.

It was our fortune to perform in the latter vessel, a passage which even up to the present time has not been exceeded. Leaving New York at five o'clock in the evening, we were landed at Catskill, a distance of one hundred and eleven miles, a quarter of an hour before midnight. Seven landings were made at intermediate places, and, if due allowance be made for these, the performance was at the rate of more than eighteen English miles per hour. The phenomena of tide on the Hudson are such, that a vessel leaving New York shortly after low water, may, at such a speed as we have mentioned, rise the river as fast as the ocean wave which causes the tide, and thus have the advantage of a favorable current for the whole distance. Such was the case in the present instance, and the tide was one of uncommon strength. Still, after making the largest possible allowance, the speed through the water was at least fourteen English miles per hour. In some recent instances, the velocity seems to have been carried as high as fifteen miles an hour through the water, and at this point, the improvement rests for the present.

We are free to admit that we, at one time, from the consideration of the received theory of the motion of bodies in fluids, were of opinion, that there was a speed which could not be exceeded, and that although this might vary according to the more or less advantageous shape of the vessel, it would, under the most favorable circumstances, be found at about 12 nautical, or 13.8 English miles per hour. This view of the subject was formed on the fact, that besides the friction, and the fluid resistance proper, varying with the square of the velocity, there was a third retarding force, increasing in a still higher rate, namely, the wave raised in the front of the vessel. Some recent experiments made in Great Britain, on the motion of vessels on canals, have shown that the sum of these several resistances, after increasing with lower velocities, begins to diminish at higher, and this to such a degree, that the greater velocities appear to be acquired with even less expenditure of moving force than the lower. So far as the wave is concerned, such has been the improvement in the models of vessels, that there are many in which the wave is not formed until the extreme breadth of the vessel enters it, and in this position, it cannot be considered as opposing any resistance.

The figure of prow, by which this property is attained, was reached by experiment. In the repeated contests of speed which occurred on the Hudson, false prows were adapted to the dif ferent vessels, and varied in form until the greatest degree of speed was acquired. The shape thus obtained was copied, in the moulds of those subsequently constructed.

The placing of the North America upon the Hudson may be considered as an epoch in the history of steam navigation. We may therefore pause to inquire into the state of the art at this period. The great improvements, by which the speed now attained has been reached, have been partially referred to. We shall repeat them here, and mention some of the other changes introduced in the engine and machinery.

1. The stroke of the piston had been increased, far beyond the proportion pointed out by Watt for engines used for manufacturing purposes. This being necessarily accompanied by an increase in the length of the crank, the circle described by its arm was much more favorably situated, in respect to the circumference of the wheel, than when the stroke was less.

2. The area of the steam pipes, valves, and steam passages, had been increased, so that the flow of the steam was more rapid; at the same time, it was not permitted to fill the whole cylinder, but was cut off at first, at half stroke. The period in the stroke at which it is now cut off, has been made as early as one eighth, in some instances.

3. The fire surfaces, in boilers of a given capacity, have been considerably increased, and the combustion rendered more intense by artificial currents of air.

4. The model of the vessels has since been improved, by diminishing the ratio of the breadth to the length, and copying the lines of the false prows, which had been found to be least resisted in practice.

The consequence of the improvements in the generation, and in the manner of using steam, and in the area of the steam pipes was such, that the velocity of the piston, which in Watt's engine is about two hundred feet per minute, was carried in the North America as high as three hundred and eighty-four feet. In some of the newly constructed vessels, the velocity of the piston far exceeds the latter limit. In the use of steam of medium pressure, acting expansively, these velocities are attained without any diminution of the average indication of the steam gauge; and in the action of the crank, an equal pressure is made to act at a higher velocity upon a more favorable point.