The Anatomy, Physiology, Morphology and Development of the Blow-Fly
by Benjamin Thompson Lowne (9781459005242)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: per day if all the oxygen is absorbed; this enables it to perform 20,000 metre-gramme units of work, or five times the work done by man, weight for weight. The Work done in Flight. ? It is well known that bodies falling through the air attain a constant velocity after a certain number of seconds, since the resistance of the air increases with the square of the velocity. Parachutes attain a constant velocity after a short time, which is determined by the resistance of the air; and it may be experimentally shown that a small parachute presenting a surface of 17 square centimetres and weighing one gramme, will attain a maximum velocity in falling of as nearly as possible one metre per second. As I find on measurement that a Cockchafer weighing one gramme has a surface of approximately 17 square centimetres when its wings and elytra are expanded, its maximum rate of falling may be taken as one metre per second. Hence one metre gramme of work per second will support it in the air. The calculation given in the appendix to this chapter, page 387, shows that this insect must expend at least i'33 metre grammes of energy per second to attain a velocity of 5 miles an hour. It may be objected that insects progress more rapidly than 5 miles an hour, but an insect weighing one gramme can only do so if it presents a less surface than 7 centimetres to the air. I have therefore calculated the maximum velocity an insect weighing one gramme could attain if it presented 3 centimetres of surface to the air. This I find to be=i2'5 metres per second, or 45 kilometres per hour, a trifle over 25 miles, with an expenditure of 22 metre grammes of work per second to attain this velocity, which is, I think, the highest possible velocity, for an insect of similar weight presenting its wings almost edge-...

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