In the Airways.

Stratford Evening Post, Volume XXV, Issue 20, 25 January 1915, Page 5

In the Airways.

NOTES ON AIRSHIPS. ZEPPELINS. "Sentinel," in the fttago Daily Times, writes: — Zeppelins are bulky airships which just now bulk largely in the wandering minds of those whose knowledge of aeronautics compasses an horizon which bounds the dome of heaveity where it meets land and water. In this aerial dome the imagination conjures up a floating terror, a long pencil-like object, rounded off at-each end with two cabins or cages fitted below, one at or near each end, equidistant from the centre of gravity. A Zeppelin possesses one or two pairs of whirring propellers. Where there are two pairs these are fitted in the fore part, underneath and on each side of the keel, just as twin screws are arranged on modern steamships. Some of the latest and largest Zeppelins are said to have four propellers, two fore and two aft; but none with four propellers have been pictured in the illustrated papers The steering gear consists of a series of planes fitted to the aft end These planes, or rudders, are used to swing the airship either laterally in the horizontal plane | or upwards or downwards in the vertical plane. The rudders for the latter movement are seldom used except when the Zeppelins are ascending from or descending to a base, or when it is necessary to cross an elevated ridge of land at a definite height. The aid of ascension is the discharge of water" or sand ballast. It -is said that when all the ballast material is y discharged the latest Zeppelins can « rise to the altitude of 10,000 ft. This, f 1 German authorities reckon, puts all m aeroplanes at a great disadvantage on r account of the extreme cold and the rarity of the atmosphere reducing the pull of their propellers, and consequently their speed. The fallacy in their reasoning is that the same holds true for the Zeppelins. In regard to the effect of cold, which is intensified by the speed of aeroplanes, the Zeppelin has the advantage, for its crew of from 20 to 35 men in an. aerial warship are housed in a room, which is artificially heated. It is said that an aeronaut travelling at the height of 7000 ft in an aeroplane becomes so cold that he can scarcely control his machine, let alone handle any offensive weapon. That is true! but it is an obstacle which may be overcome, and undoubtedly the flying staffs in Britain and France are giving this matter attention.

TYPES OF GERMAN AIRSHIPS. There are throe kinds of airships —the Sehutte-Lanze, a semi-rigid,, the Parseval, both rigid and semi-rigid, and the rigid Zeppelin. It is supposed that no Zeppelin has been used in the present war. The airship brought down and captured by "the Russians was a Parseval. The Germans say that they do not intend to use their precious Zeppelins until the day comes for attacking Britain and her fleet. All the Zeppelins are built for offensive i>i war, the others being used for both surprise attacks and observation, but chiefly for observation. Zeppelins have been used to carry passengers and, before the war, had certain routes assigned to them. They also carried the mails over these routes, am! did not fly at any great height. These air boats were used as training ships for the men joining the German aerial corps, and the passenger business was only a secondary consideration. These Zeppelins have been attached to the offensive fleet which is to act against the British, i The Sehutte-Lanze and Parsevals have some few points in which they are superior to Zeppelins; one being that they are much cheaper and much more easily constructed; but they have not the speed and fighting efficiency of the Zeppelins. The latest Zeppelins are said to have an average speed of over 60 miles an hour, and with a favorable wind they have attained a speed of 75 miles an hour. Their trouble is turning in a high wind and the leeway they make. ,« •

At the beginning of the war Germany was supposed to possess 12 airships, but Dr. Graves, the convicted spy-author, says that they probably had 30, and some Germans say that they now possess 50—the latter probably being a great exaggeration. That 30 is the most they can put in the air is nearer the truth. A year was the time Count Zeppelin took to build,a ship before the war, but it is possible that the Germans have increased the Zeppelin factories, and have done considerable speeding up. It must be remembered that, in spite of the statements that aluminium has been superseded, the Germans bought immense stocks before and after the war starteel, and much has been captured. The blockade has cut off much that they required for building these airships—for instance, rubber and brass, not to mention the aluminium from America. SIZE OF ZEPPELINS AND OTHER POINTS. Before the war started Zeppelins up to 560 ft in length and 52ft in diameter were known to be in existence; but bigger machines were under construction at the time. This shows, of course, if it is true that the numbers have so suddenly been increased. that Germany was preparing for the sudden swoop of 1914 or 1915 long before war was declared.

The later Zeppelins are said to be 700 ft or 800 ft long, and to have a proportionate increase in cross sections. If a Zeppelin gas envelope were lone continuous space, its gas capacity would be the cross section multiplied by the length. The gas does not, however, fill the whole envelope. The inside of the outer envelope contains

■: a series -of according to the size of airships. These are not close together, but each is held in ;a separate compartment built of aluminium, and- so self-contained that the destruction of one, either by bullets, or fire, does not affect the others adjacent to it. Below these balloons is 'a long corridor along which the at tendants may walk. There are spaces also where there are no;Walloons. In these spaces are kept stores of explosives' and otler- materials. There are two tubes, each running up. to the gun platforms on top, where quickfirers. 1 are mounted. The spaces thus taken up and the aluminium frameswork ..reduce the gas holding capacity fljof.'the Zeppelin to about 800,000 cubic feet, or perhaps a little more. Powerful Diesel; engines of a new type are used., The horse-power developed by these-, new machines is enormous for ■its*; siae, and the contraction secrets are jealously and effectively guarded. That is the German story. The.fore and aft cabins are roomy, and are connected by telephone and other' signalling apparatus. Men can travel from the cabin either by a wire cage or along the corridor in the envelope. Attached to each cabin there is -a gun platform. Thus, there are quickfirers above and below. Zpppc - litis are said also to have an arrange-! ment-by which they can lower a cage; to a distance of 350 ft below. This ca|je is used for dropping bombs while the. airship is concealed in the clouds alieve. . ft .is claimed- for the largest Zeppelin?; that they can carry eight tons of explosive, and more if hut thft .the authorities prefer; to-carry extra oil fuel rather than t!:e maximum, weight of explosives. lr is statedT'that the latest machines carry enftugh ; fuel for a 1500 mile journey, wßfch, of course, gives a- 750-mile radius of action from a base or hangiffi That is quite a long enough ra3ius to work from Berlin to London.