some

attending many of these speculations proves that the design was not so absurd as persons, without sufficient reason, were at the time willing to believe, and anxious to enforce. The difficulty of placing the locomotive upon the high road is not so much in the design and arrangement of the machinery as in the economy of work. The annual cost of a locomotive must always be much greater on a common road, however smooth it may be, than on a rail; partly because there is a greater resistance, but chiefly because there is a greater liability to derangement, and the necessary cost of repairs is immensely increased.

Mr. Goldsworthy Gurney was one of the first and most enterprising of those inventors who attempted to construct a steam carriage for the road. This gentleman was a scientific chemist, and his name is well known in association with the oxy-hydrogen microscope, and as the successor of Dr. Thompson to the professorship of chemistry at the Surrey Institution. In the construction of the engine, and still more of the boiler, Mr. Gurney exhibited admirable ingenuity, and by opponents as well as friends it was allowed that his trials were successful. Before an experiment was made, it was thought that the resistance between the wheels and the road would not be sufficient for the propulsion of the carriage up a steep hill, but this he practically disproved by driving the engine on several occasions up Highgate Hill, and afterwards by a journey from London to Bath.

The success of the experiments, however, increased the opposition, and one objection after another was raised, but chiefly, it must be confessed, by persons who, however honestly expressing their opinions, were interested in the failure of the invention. The possibility of a boiler explosion was perhaps the only objection indulged by the public. The quibbles of highway commissioners, and the abuse of stableboys, were merely a repetition, in a new form, of the objections before made to the railway system. But none of these impediments would have prevented the ultimate introduction of the locomotive upon the turnpike road, had not experiment proved that the cost of working it would have been greater than upon railways, and that competition in the present state of science was useless.

The rapid extension of the railway system, and the comparative safety in travelling it has produced, are little less wonderful than the improvements which have been made in the locomotive engine. There are now in the United Kingdom about six thousand five hundred miles of railway in constant work, and in the United States there are ten thousand miles in operation, and nine thousand in progress. Supposing the latter to be complete, which they will be at no distant period, the British and American railways, united as a continuous line, would encompass the earth at the equator.

CHAPTER VIII.

THE STEAM BOAT AND MARINE ENGINE.

WHEN steam was first studied in modern times. as a mechanical force, it was with the intention of applying it to the propulsion of vessels. The invention of Blasco de Garay, the Spanish seacaptain, it will be remembered, was to give motion to a vessel, and although nothing is known of his machinery, paddle wheels were employed. This idea (whether it was original, or borrowed from some preceding, but unknown inventor, we cannot tell) was never lost sight of by any subsequent mechanist. Nor is this strange, for although new discoveries are frequent in other branches of science, practical mechanics consists in the application of known, and frequently the most common agents, to new and beneficial purposes.

Papin, whom we have also mentioned as a steam engine projector, proposed to apply his design so as to move vessels against wind and tide. The mode in which he designed to accomplish this bears a close resemblance to the arrangement now adopted in steam boats. His

contrivance was to place a shaft across the vessel, and at each end to fix a paddle wheel, motion being given to the shaft by connexion with the engines. Savery, another steam engine projector, already mentioned, says that his contrivance might be very useful in ships, but that he must leave the application to those who are better acquainted with maritime affairs; strangely enough, however, he took out a patent for a shaft and paddle wheels, for the propulsion of vessels which he worked by a capstan. This engine, as he calls it, he tried on the Thames, but its usefulness, as he himself informs us, was denied by Mr. Dummer, the surveyor of the navy, because it was the same sort of contrivance that had been used at Chatham, in the year 1682, for towing government vessels, and had been employed at a loss to the crown. This, as Dr. Muirhead states, was probably the vessel made under the direction of prince Rupert, having paddle wheels worked by horses; "and which, on a trial on the Thames, witnessed by Papin, beat the king's barge, manned by sixteen rowers."

These facts, and many others might be added if necessary, prove that three hundred years ago, at least, a shaft and paddle wheels were fixed in a vessel to propel it against wind and tide. The want of a sufficiently powerful and constant force made this design useless; as the railroad waited for the locomotive, so did the shaft and paddle wheels for the marine engine. We shall, therefore, do little injustice to our subject

by passing over all the vain efforts to propel vessels without sails and oars by "new inventions and devices," and proceed at once to the examination of the history of the marine engine.

As soon as Mr. Watt had constructed his single-action steam engine, the Americans sug gested its application to the purposes of navigation, and as early as the year 1783 an attempt was made by Fitch and Rumsey to propel a vessel by steam. They failed, it is true, but more from the want of suitability in the engine to the purpose for which it was employed, than from deficiency of mechanical skill and perseverance. But their unsuccessful attempt was no discouragement to others; the design may have been for a time suspended, but was not abandoned. In 1791, John Stevens, of Hoboken, commenced the study of the steam engine and its application to navigation, and to his great honour continued his experiments for a period of sixteen years, occasionally assisted and advised by Livingstone, Roosevelt, and the elder Brunel. After this long and tedious course of investigation, conducted with ingenuity and perseverance, he was not, as he hoped to be, the first to establish a steam boat on an American river. Fulton was a few weeks before him, and during that period obtained from congress the exclusive right to navigate the Hudson with a steam vessel-a monopoly which ought not to have been granted, and was afterwards properly withdrawn as being unconstitutional.

The fact that Fulton was the first to navigate