352 THE CONQUEST OF THE AIR. 



When it was placed at the stern it acted splendidly. In the next 

 design, the ship was provided with box-shaped rudders ; in the 

 following- one with rudders arranged in Venetian blind fashion. 



The rigid type of balloon has the great advantage that pro- 

 pellers and steering gear can be attached in the most favourable 

 positions, so that indenting of the balloon is impossible, if danger 

 occurs to one or more of the separate balloons, it can still float, 

 and air ballonets are not required. The ship is thus altogether 

 better provided against the elements, once it is on its course, than 

 the non-rigid or semi-rigid types. It has the disadvantage that 

 a much greater weight has to be carried, requiring enormous 

 dimensions, and that landing on terra firma was at first a dan- 

 gerous thing. With the improved steering gear, Zeppelin proved 

 that the landing is not at all difficult. The accidents which 

 Zeppelin had were nearly all due to bad luck. At Echterdingen, 

 it was due to an electrical discharge from the framework setting 

 the gas on fire, aided by the gale which was blowing when the 

 ship seemed safely landed. The military ship was wrecked on 

 account of imperfect anchorage, the cart, used as an anchor, 

 being pulled out by a heavy gale and the ship setting off on its 

 own account. The Deutschland, the passenger ship Z7, was 

 partly wrecked on account of want of fuel for the motors, and 

 Z6 was burnt in the shed owing to the carelessness of an employe 

 coming near the motor with a bucket of benzine, which was set 

 on fire by a spark. Once proper care is taken in the handling of 

 the ship, and the country is properly supplied with landing halls, 

 accidents will be largely reduced in number. 



The ship carries two gondolas, each fitted with a 115 H.P. 

 motor made by Daimler, weighing 1,000 lbs. These motors are 

 heavy for their size, but they have the advantage of using com- 

 paratively little benzine. Each motor is able to give the ship a 

 speed of 25 miles an hour and both together of 32 miles. They 

 may be run in either direction. The ascending steering gear is 

 such that, if the planes are inclined under an angle of 15 deg. 

 at 32 miles an hour, the lift is nearly a ton. The propellors are 

 made of aluminium fixed to steel bosses. Zeppelin favours small 

 propellors running at high speeds. All bearings are of the steel 

 ball type. Behind the motors are placed the cooling tanks. Each 

 cooler is in turn cooled by a ventilator. Above each motor is an 

 oil vessel from which the oil passes to the lubricators by gravity. 

 The motors work otherwise practically in the same way as those 

 of motor cars. Besides the fuel, oil and water, for the motors, 

 each ship carries a number of water bags supplied with valves 

 and hoses as ballast. In the forward gondola are all the apparatus 

 for steering the ship. There are three hand wheels for the rud- 

 ders, two for ascending and descending. The former may be 

 manipulated separately and jointly, the latter jointly only. The 

 rudders and planes are operated by means of steel ropes which 

 are conducted over rollers between the gas balloons and the 

 external covering, and attached to the planes by means of pulleys 

 of aluminium. Communication between the gondolas takes place 

 by tin letter boxes and bells pulled by wires. A board carries the 



