The day is approaching when the air conditions will be observed and announced for the benefit of aviators exactly as the weather is foretold to-day. An aviator who is about to start on a cross-country flight will thus be able to study the conditions of the air lanes and lay out his route just as an automobilist looks up good-roads maps. In crossing a particular piece of country he will therefore know whether to take a low or a high air lane, that is, one of few hundred feet above the earth or the one several thousand feet aloft. The pressure of the air on the regular air lines will be announced as well. In this way aviation will be made much safer than it is to-day, when the aviator must venture without any knowledge of conditions aloft except those he may gain from the ground surface weather maps. During the year 1910, fully a score of lives might have been saved had aviators had such information. The first of these observation stations is actually in operation in Germany to-day. Each of these stations is supplied with a number of rubber balloons equipped with automatic apparatus for recording atmospheric conditions in the upper air lanes. The stations also contain the proper apparatus for measuring the ascensional force of the balloons, with the gas generators used for inflating the balloons. When the balloons are sent up for great heights their altitude will be measured by means of the theodolite. The soundings of the air are taken twice daily at eight o’clock in the morning and two in the afternoon whenever the weather permits. In the summer the morning observations are made much earlier. The movements of the balloons are then carefully observed at various altitudes until they are lost. These observations are then telegraphed to the central station at Lindenberg and sent out much the same as the regular weather forecast. CHAPTER XVI RULES FOR CONDUCTING MODEL AEROPLANE CONTESTS PREPARED BY THE WEST SIDE YOUNG MEN’S CHRISTIAN ASSOCIATION, NEW YORK. GENERAL RULES AND CONDITIONS FOR 1911. 1. These General Rules and Conditions shall apply to the events conducted by the West Side Y. M. C. A. 2. Each and every contestant for a prize shall accept without reservation the conditions laid down by the West Side Y. M. C. A. and shall abide by the decision of the referee. Each contestant must register his name, age and address before the event. (a) All contestants in Class "A" must be 18 years of age or over. (b) All contestant in Class "B" must be under 18 years.