rapidity as the center of the whirlwind approaches, but rises at a corresponding rate after the center has passed by; and, finally,
" That the phenomena are more uniform in large than in small storms, and more uniform on the ocean than on the land."
"These laws Mr. Redfield claimed as so many facts independent of all hypothesis—as facts deduced from the most rigorous induction, which will ever hold true, whatever views may be entertained respecting the origin and cause of storms."
Mr. Redfield's conclusions were reached after the collection and collation of as many records as possible of observations of the storms investigated, particularly of vessels which had been caught in them, the independent accounts of one storm having been one hundred and sixty-four in number; the charting of them; and the tabulation of the various data of them.
The next step was the suggestion of the methods by which vessels might avoid storms or escape them by sailing out of them.
Views like those of Mr. Redfield were reached about the same time by Dove, but Redfield knew nothing of his work. Colonel Reid, of the Royal English Engineers, at Barbadoes, who was also studying the subject, was struck with Redfield's articles, and entered into correspondence with him, which was continued to their mutual advantage. Mr. Redfield further speculated on the causes of storms—a subject which he was not able to solve, and which is still in large part a mystery.
In 1820 Mr. Redfield became interested in steamboat navigation, and ultimately associated with enterprises for carrying it on. The public had become alarmed about boiler explosions, to the detriment of the passenger traffic. To overcome their objections, Mr. Redfield devised a system of "safety barges," to be towed upon the Hudson by steamboats placed at such a distance that the passengers should be out of reach of the danger of explosions. These barges, which were in use from 1825 to 1829, attained a speed of between eight and nine miles an hour, and were in favor while the terror of explosions continued. But there came a lull in the explosions, the size and speed of the steamboats were increased, and conveyance by barges was discontinued, "to the regret," Mr. Redfield observed in a paper on the subject published in the American Journal of Science, "of those who love quiet enjoyment and whose nerves have not been inured to composure by frequent proximity with the moving power." In the same article Mr. Redfield undertook to show that the exposure to fatal accidents on board of steamboats was much less than attended the use of the ordinary means of conveyance by either land or water, and even than that from lightning. The towing system, originated by Mr. Redfield, though it lost favor as a means of conveying passengers, was extensively applied to the conveyance