plane of the gas-bag. I lay immediately under the balloon on a sort of glider framework far away from either engine or rudder, controlling them by wire-pulls constructed on the principle of the well-known Bowden brake of the cyclist.
But Lord Roberts α has been pretty exhaustively figured and described in various aeronautical publications. The unforeseen defect was the badness of the work in the silk netting. It tore aft as soon as I began to contract the balloon and the last two segments immediately bulged through the hole, exactly as an inner tube will bulge through the ruptured outer cover of a pneumatic tyre, and then the sharp edge of the torn net cut the oiled-silk of the distended last segment along a weak seam and burst it with a loud report.
Up to that point the whole thing had been going on extremely well. As a navigable balloon and before I contracted it, the Lord Roberts α was an unqualified success. It had run out of the shed admirably at nine or ten miles an hour or more, and although there was a gentle south-wester blowing, it had gone up and turned and faced it as well as any craft of the sort I have ever seen.
I lay in my customary glider position, horizontal and face downward, and the invisibility of all the machinery gave an extraordinary effect of independent levitation. Only by looking up as it were and turning my head back could I see the flat aeroplane bottom of the balloon and the rapid successive passages, swish, swish, swish of the vans of the propeller. I made a wide circle over Lady Grove and Duffield and out towards Effingham and came back quite successfully to the starting-point.
Down below in the October sunlight were my sheds