THE AUTOMATIC RECORD OF GROWTH 159 



speed of the proverbial snail becomes when magnified ten million 

 times by the Magnetic Crescograph. For this enhanced speed 

 there is no parallel even in modern gunnery. The fifteen-inch 

 cannon of the Queen Elizabeth throws out a shell with a muzzle 

 velocity of 2360 feet per second or about 8 million feet per hour ; 

 but the Crescographic snail would move at a speed of 200 million 

 feet per hour or 24 times faster than the cannon shot. Let us 

 turn to cosmic movements for a closer parallel. A point on the 

 equator whirls round at the rate of 1037 miles per hour. But 

 the Crescographic snail may well look down on the sluggish 

 earth ; for, by the time the earth makes one revolution, the 

 snail would have gone round nearly forty times ! 



Bose has been using his Magnetic Crescograph for 

 demonstration purpose before large audiences. The move- 

 ment of the spot of light indicating magnified growth is 

 seen to rush across the screen. A stop-cock is turned on, 

 admitting cooled water into the vessel containing the plant. 

 The movement of the spot slows down and ultimately 

 comes to a stop : the growth activity is now held in a 

 state of arrest, a thermometer indicating the exact tem- 

 perature-minimum. The plant-chamber becomes gradually 

 warmed, and with the removal of lethargy the growth- 

 movement is renewed, gathering increasing speed. Another 

 stop-cock turns on a depressing agent, and the growth 

 becomes paralysed ; but a dose of a stimulant instantly 

 removes the depression. The life of the plant becomes 

 subservient to the will of the experimenter ; he can exalt 

 or depress its activity ; he may thus bring it near the 

 point of death by application of poison, and when the plant 

 is hovering in an unstable poise between life and death 

 resuscitate it by the timely application of an antidote. It 

 all looks like magic ! But are not the achievements of 

 science more wonderful than magic ? 



'It is by the extension of man's power beyond his 

 sense-limitations that he is enabled to probe into the 

 deeper mysteries of nature.' 



The enthusiasm aroused during Bose's recent scientific 

 visit to England (1919-20) is not a little due to the 



