A GIFT OF GOD 17 



to flight through its own weight and momentum. Once 

 the pace has been gathered by the wing, the body 

 comes into play. This is well shown in those constant 

 intervals during the partridge's, chaffinch's, or wood- 

 pecker's flight when the wings are quite passive, shut. 

 During the intervals the partridge is still moving 

 quickly on its straight line, the woodpecker or chaf- 

 finch quickly through the second part of its arc or 

 parabola ; the machine is simply moving through the 

 momentum of the body, the wings being out of play. 

 Is not, then, the case just that of a train when the 

 driver has shut off steam but not applied his brake, 

 and the train is moving by the great momentum of 

 its own body ? When the chaffinch starts flying its 

 wings are worked much harder than when it has been 

 moving at a good pace for several minutes. Once 

 launched and moving quickly, it describes through 

 space arcs of some length, five or six yards. I believe 

 that could we time a chaffinch or a woodpecker on a 

 two mile journey at a good pace, we should find that 

 the moments when the wings are acting are consider- 

 ably less than the moments during which the wings 

 are passive. It is because the body itself, thanks to 

 shape, poise, and weight, can economise the strength 

 of the wing that birds can live through great migra- 

 tions. The flying machine can thus travel at high 

 speed, hundreds of miles at a stretch, without 

 failing ; and if at length it does break down, the 

 fault lies not in its mechanism, which is absolute 



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