EARLY EXPERIMENTS IN AIR FLIGHT. 603 



EAELY EXPEKIMENTS m AIK FLIGHT. 



By M. BANET rivet. 



MAN^ has souglit in all times and at all places to find means 

 of leaving the earth's surface, in imitation of the birds, and 

 rising into the air. Ancient legendary lore furnishes many stories, 

 like those of Daedalus and his son Icarus, of attempts of this sort. 

 In the fourth century b. c, Archytas of Tarentum, a learned 

 Pythagorean, who has been credited with the invention of the 

 screw, the pulley, and the kite, according to Aulus Gellius, con- 

 structed a wooden dove which could rise and sustain itself in the 

 air by some mechanism the arrangement of which is not known. 

 Credible accounts exist of an English Benedictine monk, Oliver of 

 Malmesbury, in the eleventh century, having tried to fly by pre- 

 cipitating himself from the height of a tower, with the assistance 

 of wings attached to his arms and his feet. It is said that, after 

 having gone along a little way, he fell and broke his legs. He 

 attributed his accident to failure to provide his apparatus with a 

 tail, which would have helped preserve his equilibrium and made 

 the descent a gentler one. 



In the sixteenth century, Leonardo da Vinci first demonstrated 

 that a bird, which is heavier than the air, sustains itself, advances 

 in the air, " by rendering the fluid denser where it passes than 

 where it does not pass." In order to fly it has to fix its point 

 of support on the air; its wing in the descending stroke exerts a 

 pressure from above down, the reaction of which from below up 

 forces the center of gravity of its body to ascend at each instant 

 to the height at which the bird wishes to maintain it. Some 

 sketches that have come down to us prove that Leonardo occupied 

 himself, like Oliver of Malmesbury, with giving man power to 

 fly by the aid of mngs suitably fixed to his body. We owe to 

 Leonardo also the invention of the parachute, which he described 

 in the following terms: "If a man had a pavilion, each side of 

 which was fifteen braces mde and twelve braces high, he might 

 cast himseK from any height whatever, without fear of danger." 

 It may be said, too, of Leonardo da Vinci, that he was the first 

 to suggest the idea of the screw propeller. " If," he said, " this 

 instrument in the form of a screw is properly made — that is, made 

 of linen cloth, the interstices of which have been filled with starch 

 — and if we turn it rapidly, such a screw will make a bearing nut 

 for itself through the air and rise. This can be proved by mov- 

 ing a broad, thin rule rapidly thl-ough the air, when it will be 

 found that the arm is forced to follow in the direction of the edge 



