THE COMING OF THE ZEPPELINS.
On page 144 of our first volume I gave you a brief account of the great airship invented by Count Zeppelin and called after his name. It is said that the newest type of Zeppelin is about 700 feet long, and has eighteen compartments, which hold about a million cubic feet of hydrogen. Each compartment is a separate balloon, and in theory the airship can remain afloat if two of the balloons are damaged. The framework is of wood and aluminium. The engines, guns, stores, and crew are contained in two cars or gondolas, which are built into the framework of the airship, almost flush with its keel. The engines are four in number, and drive the propellers, a pair being coupled to each car, two forward and two astern. When they are working they make a terrible din, and a Zeppelin thus advertises his approach.
Some of the latest vessels have a speed of from forty to sixty miles an hour. Two sets of rudders are provided—one set for steering the ship horizontally, and one set to guide it when ascending or descending. It can ascend with remarkable speed—it is said that a modern Zeppelin can soar upwards at a speed of 4,500 feet per minute, and can reach the safety zone of about 12,000 feet almost before artillery on the ground has secured the range. A large Zeppelin can carry about seventeen tons, of which about two tons consist of explosives. All Zeppelins are fitted with powerful searchlights, and a car which can be let down from the gondola by steel ropes so as to enable the men in it to make observations from a lower level. The weakest part of a Zeppelin is its upper envelope. Attacking aeroplanes always endeavour to rise above the airship in order to drop bombs upon it. You will remember that Warneford destroyed his Zeppelin in this way.
