the Flying-Jlsh Problem. 



331 



extend from 30 to 50 yards in less than twenty seconds." la 

 order to get working figures we may call "30 to 50 yards ^' 

 403'ards, and " less than twenty seconds" 15 seconds. This 

 gives a rate of 5i miles an hour ! 



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

 steamer. 



Such statements are the habit of the problem. Just in 

 the same way is it its recognized habit to quote, un- 

 questioned, as " sailing " parallels to the heavy smali- 

 winged fish, the f-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 eflbrts 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 (Hartings' formula) of a swallow (house-martin) 

 is 4*2, and its wing-area 120 sq. era. 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. 



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

 parts of the sketch. 



Could anyone contend that a swallow could sail even in its 

 present poor and much-assisted way (for it is far from being 

 a first-class sailer) if the unshaded parts of the wing-areas 

 were removed ? 



Opinion is, however, undoubtedly changing. Many of the 

 old shibboleths are fast becoming discredited. The great 

 distances that the fish, under favouring conditions, fly clear 



