(234.)

Nothing has excited more surprise among engineers and others interested in steam navigation in Europe, than the statements which have been so generally and so confidently made of the speed attained by American steamers. This astonishment is due to several causes, the chief of which is the omission of all notice of the great difference between the structure and operation of the American steamers and the nature of the navigation in which they are engaged, compared with the structure and operation of, and the navigation in which European steamers are employed: as well might the performance of a Thames wherry, or one of the fly-boats on the northern canals, be compared with that of the Great Western, or the British Queen. The statements alluded to all have reference to steamers navigating the Hudson between New York and Albany, the form and structure of which we have already described; and doubtless the greatest speed ever attained on the surface of water has been exhibited in the passages of these vessels.

Mr. Stevenson states, that exclusive of the time lost in stoppages, the voyage between New York and Albany is usually made in ten hours. Dr. Renwick, however, who has probably more extensive opportunities of observation, states, that the average time, exclusive of stoppages, is ten hours and a half. The distance being 125·18 geographical miles, the average rate would therefore be 119⁄10 miles per hour. If it be observed that the average rate of some of the best sea-going steamers in Europe obtained from experiments [Pg499] and observations made by myself, more than three years ago, showed a rate of steaming little less than ten geographical miles per hour, and that since that time considerable improvements in steam navigation have been made, and further, that these performances were made under exposure to all the disadvantages of an open sea, the difference between them and the performance of the American river steamers will cease to create astonishment.

Dr. Renwick states that he made, in a boat called the "New Philadelphia," one of the most remarkable passages ever performed. He left New York at five in the afternoon, with the first of the flood, and landed at Catskill, distant 95·8 geographical miles from New York, at a quarter before twelve. Passengers were landed and taken in at seven intermediate points: the rate, including stoppages, was therefore 14·2 miles per hour; and if half an hour be allowed for stoppages, the actual average rate of motion would be fifteen miles and three quarters an hour. As the current, which in this case was with the course of the vessel, did not exceed three miles and a half an hour, the absolute velocity through the water would have been somewhat under twelve miles an hour. This speed is nearly the same as the speed obtained from taking the average time of the voyages between New York and Albany at ten hours and a half; it would therefore appear that the great speed attained in this trip must have been chiefly, if not altogether, owing to the effect of the current.