Avoiding Zeppelins

Abstract

A LITTLE knowledge of spherical perspective would materially reduce the loss of life due to Zeppelins. There is no danger from a bomb dropped by one of these vessels unless the latter is approaching the zenith, and will reach there in a few seconds. If the Zeppelin appears inclined—that is, unless one end appears exactly over the other—there is no danger. This is easily seen at a glance, but a plumb-line formed by a stone attached to a string will show this with certainty. The Zeppelin will always pass on the side towards which the upper end points. If, however, it is vertical, and near the zenith, there is great danger. If its altitude is, for example, a mile, a bomb dropped would occupy 18 seconds in falling, if there were no air. Owing to the resistance of the latter, this time is greatly increased. It is only necessary to run at right angles to the apparent direction of the Zeppelin to be safe, even if one does not start until the bomb is dropped. This rule may be tested by standing under a telephone wire, which may be regarded as representing the path of the Zeppelin. A plumb-line will cover the wire only if the observer is exactly under the wire. No allowance is here made for the wind, which always carries the Zeppelin to leeward. It may be better, therefore, to stand so that the Zeppelin is partially covered by the edge of a house, a flagpole, or other vertical line. There is no danger unless the Zeppelin appears to ascend the line, remaining partially covered as it approaches the zenith. The same principles apply to aeroplanes. At sea, the vessel should take a course at right angles to the direction from which the Zeppelin comes. Of course, these methods are useless if the Zeppelin cannot be seen owing to clouds or darkness, unless it is picked up by a searchlight.