Professor Ward Shows Need of a Chart of the Atmosphere for all Aviators.

There is no need of emphasizing the importance of a knowledge of meteorology on the part of those whose business it is to sail through the ocean of air. This ocean has its tides; its currents; its waves. It is beginning to be charted, but only just beginning. The late Professor A. Lawrence Rotch, founder and director of the Blue Hill Observatory, which he left to Harvard, with an endowment, in his will, was a pioneer in charting the atmosphere. Shortly before his death, Professor Rotch published his "Charts of the Atmosphere for Aeronauts and Aviators." This volume presents, in a practical form, some of the results obtained at Blue Hill during twenty years of observation. The charts are the first of their kind adapted to the use of flyers.

Must Know How to Navigate.

A seaman navigates his vessel in all sorts of weather, but skill in local weather forecasting, and a practical knowledge of the laws of storms, are invaluable in making possible a speedier, safer and more successful voyage. Similarly, the navigator of the air, though war service often involves flying under atmospheric conditions far from favorable, inevitably finds, sooner or later, that the more he knows about the air which he is navigating, the better equipped he is as a fighter, as a photographer, or on reconnaissance work. At critical times, meteorological knowledge has time and again proved its practical value to those who navigate the air. It is true enough that meteorologists still have but a very imperfect idea of much that concerns the upper air currents, but what they do know they are now putting at the service of the men who fly. And the men who fly will, in their turn, enrich and advance meteorological science by means of the many important facts which their own practical experience in the air will impress upon their minds. The man who knows most about practical meteorology is the best equipped for service in the air. He is the most likely, other things being equal, to do his country the greatest service.

The military aviator must have his meteorological facts presented in the simplest, clearest, and most practical way. Meteorology is but a small part of the varied and highly complex information which is necessary in his exacting and dangerous occupation. Theories should be omitted altogether, and explanations, except of certain essential facts, are unnecessary. The keynote of the meteorologist's contribution to the training for flying in war is the desire to make aviation more effective as a means of waging war and the hope of being able to save the lives of some of our flyers