“Phew!” exclaimed Billy Barnes as he reported for work on the New York Planet one broiling afternoon in late August, “this is a scorcher and no mistake.”“I should think after all your marvelous adventures with the Boy Aviators that you would be so used to heat and cold and hardship that you wouldn’t kick at a little thing like a warm day.”The remark came from a young fellow about twenty-one years old who occupied a desk beside that of the stout spectacled youth of eighteen whom our readers have already met as Billy Barnes.