No. 482] THE FLYING-FISH PROBLEM 



Take a quite typical example of the common aeroplane blind- 

 fold acceptance from writer to writer of palpable impossibilities 

 as guiding facts. In the article that we have been quoting from 

 we may note the following (p. 500): "The best estimate has been 

 that an ordinary flight may extend from 30 to 50 yards in less than 

 twenty seconds." In order to get working figures we may call 

 "30 to 50 yards" 40 yards, and "less than twenty seconds" 15 

 seconds. This gives a rate of 5^ miles an hour! 



Note this, you who watch the fish fleeing before a 14-knot 



Such statements are the habit of the problem. Just in the 

 same way is it its recognized habit to quote, unquestioned, as "sail- 

 ing" parallels to the heavy small-winged fish, the |-oz. large- 

 winged swallow, and the parachute whose work is falling only; 

 or, again, to faithfully reproduce over and over again pictures of 

 impossible air-currents performing feats also impossible; or to 

 continue to ascribe the frantic efforts at flight of a fish fallen on 

 deck to natural spasms, although it is not credited with active use 



of its wings either in air or sea; and so on. It is the way of the 

 problem, and no one is to blame. 



Perhaps the odd unsuitability of the swallow comparison may 

 be brought more fully home by a sketch. 



The ratio (Harting's formula) of a swallow (house-martin) is 

 4.2, and its wing-area 120 sq. cm. The flying-fish ratio is 2.6. 

 If we reduce the swallow to a 2.6 ratio, its wing-area becomes about 

 47 sq. cm. 



This reduction to flying-fish ratio is shown by the shaded parts 

 of the sketch. 



