Ericsson's studies and improvements of the screw as a means of propelling boats began in England. A model boat, two feet long, fitted up with two screws, was launched in a London bath-house, and, supplied by steam from a boiler placed at the side of the tank, was sent around at a speed estimated at six miles an hour. Ericsson was so delighted with it that he built a boat eight feet by forty, armed with two propellers, in the hope that the British Admiralty might adopt the invention. This boat went through the water at the rate of ten miles an hour, or seven miles an hour towing a schooner of one hundred and forty tons burden. He invited the Admiralty to see the work of his screw. Steaming up to Somerset House with his little vessel, Ericsson took the Admiralty barge in tow, to the wonder of the watermen, who could make nothing of the novel craft with no apparent means of propulsion. The British Admiralty, however, was not easily convinced. These wiseacres said nothing, but Ericsson professed to have heard that their verdict was against him because one of the authorities of the board decided that "even if the propeller had the power of propelling a vessel it would be found altogether useless in practice, because the power, being applied to the stern, it would be absolutely impossible to make the vessel steer." This official blindness cost England the services of the inventor. The United States happened to have as consul in Liverpool at that day (1837) Mr. Francis B. Ogden, a pioneer in steam navigation on the Ohio River. Ogden saw Ericsson's invention and introduced him to Captain Robert F. Stockton, of the United States Navy. With Stockton, seeing was believing, and when he returned from a trip on Ericsson's boat, he exclaimed: "I do not want the opinion of your scientific men. What I have seen to-day satisfies me." Before the vessel had completed her trip, Ericsson received from Stockton an order for two boats. Upon Stockton's assurance that the United States would try his propeller upon a large scale, Ericsson closed up his affairs in England and embarked for the United States. Through the good offices of Stockton, but after considerable delay, a vessel called the Princeton was ordered and completed. She carried a number of radical improvements destined to make a revolution in naval warfare. The boilers and engines were below the waterline, out of the way of shot and shell. The smoke-stack was a telescopic affair, replacing the tall pipe that formed so conspicuous a target upon the old boats. Centrifugal blowers in the hold, worked by separate engines, secured increased draught for the furnaces. The Princeton was a wonder, and everyone was ready to praise the inventive genius of Ericsson and the daring of Captain Stockton in adopting so many radical novelties. An entry in the diary of John Quincy Adams, dated February 28, 1844, tells the sad story of the public exhibition of the Princeton at Washington: