The inventions projected, though in many instances not perfected or successfully introduced, by Mr. Cooper constitute a long list and cover a wide field. A few of them may be mentioned here, in addition to those to which allusion has been made already. It will be seen that even those which failed of commercial success generally contained the germs of future mechanical progress, and bore witness to the extraordinary vigor and versatility of his genius.

When the Erie Canal was approaching completion it occurred to Mr. Cooper that canal boats might be propelled by the power of water drawn from a higher level and moving a series of endless chains along the canal. After some preliminary experiments he built a flat-bottomed scow, arranged a water wheel to utilize the tidal current in the East River, and actually achieved a trial trip of two miles and return, in which Governor Clinton and other invited guests took part. The governor was so well pleased that he paid Mr. Cooper eight hundred dollars for the first chance to purchase the right of applying the method on the new canal. But the scheme failed for the reason (as Mr. Cooper explained half a century later) that the right of way for the Erie Canal had been secured from the farmers of the State by representing to them the profit which they would realize from selling forage, etc., for the use of canal boats, which were to be drawn by horses or mules. The introduction of mechanical power would destroy these inducements, and the plan was abandoned,—though Mr. Cooper had demonstrated its feasibility by running his endless chain on the East River for ten days and carrying hundreds of passengers over the trial route. It is not likely that such a use of water power on the Erie Canal would have proved practicable on a large scale; but the endless chain, which Mr. Cooper apparently considered as a minor feature only, has been adopted since, and lies at the basis of the famous Belgian system of river and canal transportation.

In 1824 the wave of enthusiastic sympathy for the Greeks which swept over the country upon receipt of the tidings of their revolt against Turkish tyranny stimulated Mr. Cooper to invent a torpedo boat, to be steered from the shore by "two steel wires, like the reins of a horse." But on the trial trip of the boat a ship crossed and broke the wires when about six of their total length of ten miles had been let out. The delay made the invention too late for use by the Greeks, and it was not further pursued.

About 1835 the subject of aerial navigation had in the United States one of its periodical revivals. Mr. Cooper, believing that a motive power developed from materials of small weight was essential to the solution of the problem, resolved to employ the explosive force of chloride of nitrogen,—one of the most dangerous compounds known to chemists. The result of his experiments in this direction was an explosion which blew his apparatus to pieces, and nearly cost the audacious inventor an eye. In fact, though the organ was saved from total destruction, it was permanently injured.

The conveyance of freight by aerial cables—a method now widely used—was practiced by Mr. Cooper at an early day. The use of elevators in buildings was foreseen and provided for by him in the erection of the Cooper Union building, and in that building also he introduced for the first time iron beams as part of a fire-proof construction. In these and other inventions his prophetic intuitions were illustrated.

But such intuitions do not fully take the place of scientific training; and one of the inventions of Peter Cooper—which he considered for many years, and possibly to the very last, as his crowning achievement—was a curious example of misdirected ingenuity. It is worthy of notice here, however, for another reason, namely, because of its accidental association with one of its inventor's most remarkable triumphs.

As a young apprentice he had studied the steam engine, and had resolved that he would improve it by doing away with the crank. To his mind this was a source of great loss of power, and he believed that, if he could transform the rectilinear motion of the piston rod directly into rotary motion without the intervention of the crank, he would effect a notable economy.

Now, there is no such loss of power through the crank as he imagined, nor is it likely that any other device for obtaining rotary from rectilinear motion will be found superior to that which Watt devised. But Peter Cooper assailed this fancied evil with undoubting confidence, both as to its existence and as to his ability to do away with it. The result was an invention for which he received, April 28, 1828, letters patent of the United States. At that early day patents were comparatively few,—so few that this one bears no number; and the duties of general administration did not prevent the highest officials from attending to details. This patent, issued to Peter Cooper, of New York, was personally signed by John Quincy Adams, President; countersigned by Henry Clay, Secretary of State; transmitted to William Wirt, Attorney-General; examined, approved, and signed by him, and returned to the Department of State for final delivery to the patentee. It grants for fourteen years to the said Peter Cooper, his heirs, administrators, and assignees the exclusive right to make, use, or license others to use, the described improvement in the method of effecting rotary motion directly from the alternate rectilinear motion of a steam piston. Evidently these distinguished statesmen—Adams, Clay, and Wirt—were not experts in mechanics, or at least did not undertake to hinder by technical criticism the experiments of American ambition; and there was no trained corps of patent-examiners to decide upon the novelty, practicability, and usefulness of any proposed improvement in the arts. Probably the government shared at that time the dominant American feeling of unconquerable youth, ready to attack all problems, especially those which previous experience had pronounced insoluble, and to determine the impossible by attempting it. This spirit has in fact more or less dominated the United States Patent Office down to the present time. With all its present equipment of examiners, trained in theory and versed in technical literature, it still concerns itself chiefly in the consideration of a proposed invention with the question of novelty, rather than that of feasibility or value; and the effect has been that, while thousands of patents are granted for absurd, unnecessary, or inoperative devices, the net result of the encouragement thus given to individual ingenuity and audacity is a catalogue of great inventions unmatched in the history of any other nation.

The patent of Peter Cooper, which now lies before me,—a time-stained parchment bearing the great seal of the United States and the autographs of the famous men named above,—is accompanied by no drawings; but it contains a detailed specification which shows that the invention consisted in an arrangement by which, at each forward movement, a prolongation of the piston rod clawed into an endless chain, which was pulled back by the return stroke. This chain passed around a wheel, to which it consequently imparted a rotary motion.

Engineers do not need to be told that this cumbrous arrangement could not successfully replace the crank, even if such a replacement were desirable. Yet the inventor constructed a working-machine, and satisfied himself, by a "duty trial" of some sort, that it "saved two fifths of the steam." His discovery, however, was not hailed with immediate recognition by the mechanical public; and its author, undisturbed in his faith, bided his time.

This, by the way, points to a characteristic of Peter Cooper, differentiating him from the numerous enthusiasts whom prudent men are accustomed to avoid. He was not a man "of one idea." His fertile and ingenious mind threw out its suggestions in every direction, into fields untrodden by experience; but when any such plan failed of acceptance, he turned, with undiminished courage and hope, to something else, remaining, nevertheless, still steadfast in his former conception, and ready to seize any opportunity for its realization.

Thus it came to pass that Mr. Cooper's abortive improvement upon the steam engine was the source of his fame as the builder of the first American locomotive, as the following chapter will explain.