THE ZEPPELIN AIR SHIP. 219 



and the whole interior, looked at from one end, appears as if a lot of 

 bicycle wheels had been placed side by side. The whole series of 

 seventeen sections is covered with a tough and light network of ramie. 



Each section, as we have said, is a balloon in itself, and each section 

 is covered with a light silk texture, which by virtue of an india-rubber 

 coating is, in the general sense of the word, gastight. So tight, 

 indeed, has each balloon been made that one filling of hydrogen (the 

 lightest and most volatile of gases) has been proved to last for two or 

 three weeks. 



The exterior of the balloon is made of pegamoid, which protects it 

 both from sun and rain. The total capacity of the interior balloons 

 is about 12,000 cubic yards of hydrogen gas; and, lest any of our 

 readers should bankrupt himself by attempting to construct a Zep- 

 pelin l)alloon, we may as well add that each filling costs in the neighbor- 

 hood of -£'50(t. When the balloon is read}' to ])e tilled the h3'drogen 

 gas, in 2,200 iron bottles, is brought alongside the balloon shed on 

 pontoons, each containing 130 l)ottles and all connected with each 

 other, thus forming a single reservoir, which in turn is connected with 

 the balloon by a distributing pipe. It takes tive hours to fill the 

 whole balloon. 



It is one thing to build a balloon and another thing to make it go. 

 It is still another thing to be able to control its flight, steering it this 

 way and that, with the wind and against it. Hundreds of inventors, 

 including the lamented Darius Green, have failed because of their 

 methods of steering and propulsion, or the absence of each. But it 

 is in these very respects that Count Zeppelin may well be said to have 

 been successful, More, however, of that anon. Suflice to say here 

 that the propulsion of the great balloon under consideration is efl'ected 

 ])y four screws made of aluminum, all working as do the propellers 

 of a ship. Two of these screws are situated about a third of the 

 total length from the bow. and the other two a like distance from the 

 stern. Each screw makes over a thousand revolutions a minute. 



In several of our illustrations the cars of the balloon are plainlv 

 shown. These also are made of aluminum — indeed every part of the 

 air sliip is made of the lightest possible material— and are attached to 

 the inner framework b^^ rods and wires. The cars are about 5 feet 

 broad and 3 feet deep and are situated each under a pair of screws, 

 which may be noted projecting from the sides of the balloon. The 

 cars carry the motors for driving the propellers, and benzine, by vir- 

 tue of not requiring such heavy machinery to use it with, has been 

 chosen for the motive power. Enough benzine may be carried to 

 work the balloon for ten successive hours. It may be added that the 

 cars of the balloon are connected, as shown in our photographs, by a 

 narrow passageway, made of aluminum wires and plates, which are 

 tirml}' connected with the balloon above. 



