So I built my "No. 9," the smallest of possible dirigibles, yet very practical indeed. As originally constructed, its balloons capacity was but 220 cubic metres (7770 cubic feet), permitting me to take up less than 30 kilogrammes (66 lbs.) of ballast—and thus I navigated it for weeks, without inconvenience. Even when I enlarged its balloon to 261 cubic metres (9218 cubic feet) the balloon of my "No. 6," in which I won the Deutsch prize, would have made almost three of it, while that of my "Omnibus" is fully eight times its size. As I have already stated, its 3 horse-power Clement motor weighs but 12 kilogrammes (26½" lbs.). With such a motor one cannot expect great speed; nevertheless, this handy little runabout takes me over the Bois at between 20 and 25 kilometres (12 and 15 miles) per hour, and this notwithstanding its egg-shaped form (Fig. 15), which would seemingly be little calculated for cutting the air. Indeed, to make it respond promptly to the rudder, I drive it thick end first.
Fig. 15
I have said that, as it was originally proportioned, the balloon of this smallest of possible dirigibles permitted me to take up less than 30 kilogrammes (66 lbs.) of ballast. As now enlarged its lifting power is greater; but when account is taken of my own weight and the weight of keel, motor, screw, and machinery, the whole system becomes neither lighter nor heavier than the surrounding atmosphere when I have loaded it with 60 kilogrammes (132 lbs.) of ballast; and it is just in this connection that it will be easiest to explain why I have called this little air-ship very practical. On Monday, 29th June 1903, I landed with it on the grounds of the Aéro Club at St Cloud in the midst of six inflated spherical balloons. After a short call I started off again.
"Can we not give you some gas?" politely asked my fellow-clubmen.
"No. 9." SHOWING RELATIVE SIZE
"You saw me coming all the way from Neuilly," I replied; "did I throw out any ballast?"
"You threw out no ballast," they admitted.