By the kindness of the Superintendent of the Coast Survey, the house-boat was towed in May, 1893, down to Chopawamsic Island, a small island near the western bank of the Potomac River, not far from the Quantico station of the Washington and Richmond Railroad Company. A map of the island and the adjacent land and water is shown in Plate 19. The house-boat was at all times moored somewhere on the west side of the island, in the stretch of quiet water between that and the west shore of the river. The waters shown here are, with the exception of a narrow channel, very shallow, and, indeed, partly dry at low tide, so that there was no danger of an aerodrome being lost, unless its flight carried it a long distance away and over the land. FIELD TRIALS[29] Aerodrome No. 4, as shown in Plate 11, had a single midrod, a flying weight of 9 pounds,[30] and supporting surface, consisting of wings and tail, of 18 square feet. [p094] Its engines, with about 100 pounds pressure, developed an aggregate of 0.4 H. P., and lifted 50 per cent of the flying weight. The propellers were 60 cm. (2 feet) in diameter and 1-1/4 pitch ratio. The aerodrome was intended to be launched by a contrivance called the “starter,” which was an inclined rod, hinged at the bottom, on the top of which the aerodrome was supported on a rod which was thrown down at the instant of flight, giving the aerodrome a slight forward impulse, with the expectation that it would get up sufficient initial speed to soar from the action of its propellers. On November 18 the writer (L), with Dr. Barus (B) and the two mechanics (R and M), went to Quantico by an early train, and superintended with interested expectation the arrangements for this first trial in the open air of the mechanism which had now been over two years in preparation. We met with an unexpected difficulty—that of launching the aerodrome at all, for though the wind was only a very gentle breeze, it was only by holding it down with the hands that it was possible to keep the aerodrome in position for the launch, during the few minutes which passed from the time it was placed upon the apparatus to the time of releasing it. Whether the launching device itself might be effective or not could not be ascertained, since it was found that nothing which could even be called an attempt to launch could be made except in an absolute calm; a condition of things very difficult for any one to understand who has not passed through the experience. The writer returned to Washington at the close of the day without having done anything, but having learned a great deal.