About 1837 there existed in Philadelphia an organization called the Franklin Kite Club that flew kites for recreation. Espy, the eminent meteorologist, was a member, and he states "that on those days when columnar clouds form rapidly and numerously the kite was frequently carried upward nearly perpendicularly by columns of ascending air," a phenomenon which is often observed to-day. Espy calculated the height at which clouds should form by the cooling of the air to its dew-point, and then employed kites to verify his calculations of the heights of the clouds. It will be remembered that both these methods are utilized in the measurements of cloud-heights at Blue Hill. Kites were employed to get temperatures a hundred or more feet above the Arctic ocean early in the present century, and in 1847 W. R. Birt flew a kite at Kew Observatory, with which he hoped to obtain measures of temperature, humidity, wind velocity, etc. This kite, hexagonal in shape, required three divergent strings attached to the ground to keep it steady, and the instruments were to be hoisted up to the kite by a pulley. Perhaps the first person to soar aloft on a kite was a lady, who, more than fifty years ago, was lifted some hundred feet by a great kite constructed by George Pocock, an Englishman, to serve as an aÎrial observatory in warfare, and also to drag carriages along the ground. It was proposed afterwards to make use of kites in shipwrecks to take persons or life-lines ashore, and in 1865 Sir George Nares invented a storm-kite, so called, with a tail made up of hollow cones. This form of tail, subsequently used for both kites and balloons, is very efficient, since it offers increasing resistance as the wind becomes stronger.