Читать книгу Andrée and His Balloon онлайн

18 страница из 42

The valve is guided in its course by a central steel tube, sliding in another tube, which serves as an axis for the frame. A small cotter limits its action, the length of which is equal to one-half of the radius of the discharge orifice. The joint is rendered gas-tight at the periphery of the valve by means of a brass blade resting on a rubber band stretched in a groove of the seat.

The valve commences to open under the action of an internal pressure corresponding to ³⁄₁₀ inch water column. In order to fix it to the balloon, it is placed in the interior of the appendage, the margin of which, held between two rubber bands, is kept tight against the seat by an external belt or ring of brass, fastened by bolts.

“Rending Flap.”—The rending flap is 4½ yards high, and has a surface of 4⁷⁄₁₀ square yards. It is formed of threefold Pongee silk, and is rectangular in shape, terminating in a curvilinear triangle, the point of which is turned upwards. Its vertical axis is at an angular distance of 105 degrees from each of the two manipulating valves; the lower base, which is 35⅖ inches wide, reaches down to 19⅗ inches above the equator. The seams joining the material of the “rending flap” to that of the balloon are similar to the seams of the various widths, and are likewise covered with cemented strips.