Page:My Airships.djvu/260

 Carlo, except in perfect calm, must always be a still different proposition. Nor can any accurate calculations be based on the markings of the anemometer, an instrument which I, nevertheless, carried. Out of simple curiosity I made note of its readings on several occasions during my trip of 12th February 1902. It seemed to be marking between 32 and 37 kilometres (20 and 23 miles) per hour; but the wind, complicated by side gusts, acting at the same time on the air-ship and the wings of the anemometer windmill—i.e. on two moving systems whose inertia cannot possibly be compared—would alone be sufficient to falsify the result. When, therefore, I state that, according to my best judgment, the average of my speed through the air on those flights was between 30 and 35 kilometres (18 and 22 miles) per hour, it will be understood that it refers to speed through the air whether the air be still or moving and to speed retarded by the dragging of the maritime guide rope. Putting this adverse influence at the moderate figure of 7 kilometres (4$\tfrac{1}{2}$ miles) per hour my speed through the still or moving air would be between 37 and 42 kilometres (22 and 27 miles) per hour.