July 4, 1919] 



SCIENCE 



21 



amplitude. Wlien near one end of the path 

 the length of the pendulum is increased, and 

 ■when near the middle of the path the length 

 is decreased. In the course of a few swings 

 the amplitude can be very greatly increased. 

 The process can also be reversed and the mo- 

 tion of the pendulum very quickly damped. 



The increase in the energy of the penduliun 

 as its amplitude increases comes from the 

 work done in lifting the bob when near the 

 middle of its path. This is because a given 

 change in the length of the pendulum involves 

 a greater vertical displacement when the pen- 

 dulum is nearly vertical than when it is much 

 inclined to the vertical. 



Arthur Taber Jones 



Smith College, 



a quick method of eliminating seed- 

 borne organisms of grain 



The seed-borne diseases of grain have 

 proved difficult to definitely eliminate from 

 the seed. In connection with studies of hot 

 formaldehyde as a fungicide for potato dis- 

 eases it was tried for wheat scab. It was soon 

 apparent that holding the grain in a formalde- 

 hyde solution at 50° C. as for potato scab 

 was ineffective in killing the fungus or de- 

 structive to the viability of the seed. In order 

 to overcome these difficulties the grain was 

 suspended just above the formaldehyde solu- 

 tion one part in 240 parts of water and the 

 temperature was raised to 98 to 99° C. and 

 the time of exposure shortened to twenty 

 seconds. Under these conditions all fungi in 

 or on the seed were killed and in the majority 

 of cases the bacteria were also eliminated. 

 This momentary treatment did not injure the 

 germinating capacity of the seed. The fungus 

 flora of wheat seeds were destroyed in twenty 

 seconds while the germinating capacity of the 

 grain was not injured in forty seconds and 

 only slightly at fifty. It is believed this 

 method can be made practical for the control 

 of scab and other seed borne diseases of grain. 

 I. E. Melhus, 

 L. L. Ehodes 



Iowa Experiment Station, 

 Ames, Iowa 



SCIENTIFIC BOOKS 



The Grand Fleet, 19U-1916: Its Creation, 

 Development and Work. By Admiral Vis- 

 count Jellicoe of Seapa. ITew York, Geo. 

 H. Doran Co. 1919. 



One hardly expects a critical review of a 

 book of this character except in military jour- 

 nals. Yet, this book is a plain, unvarnished 

 narrative of the meeting in battle of the two 

 great fleets of Great Britain and Germany. 

 Jutland was the culmination of a struggle for 

 supremacy on the seas and back of that for 

 world domination. It was essentially a try- 

 out of scientific methods of annihilation as 

 developed and adopted by the two leading na- 

 tions of the world. The book might well 

 carry as a sub-title " Science in Naval War- 

 fare up to 1916." And therefore brief com- 

 ment upon the scientific methods of the op- 

 ponents is not out of place here, for we all 

 know now that professional military and naval 

 men have to lean and lean heavily upon non- 

 official scientific men. 



The battle of Jutland as described in this 

 book reminds one of a Homeric conflict, for 

 just when some great captain had closed with 

 his antagonist, the watching gods, disguised 

 as mists, fogs and poor visibility intervened 

 and separated the fighters. Much as we would 

 like to compliment the British, the palm for 

 preparation and scientific attainment must go 

 to the Germans. The British had more ships 

 and more guns; but the Germans had better 

 range finders, better telescopic sights, better 

 mine fields, better torpedoes, better subma- 

 rines and more of them, better overhead ob- 

 servation facilities and a Zeppelin or two. 

 The Grand Fleet (British) appears to have 

 made use of a single seaplane which flew very 

 low, yet whose observations as Vice Admiral 

 Beatty says, were " of distinct value." 



The German battleships were of greater dis- 

 placement than contemporary British ships 

 and carried a greater weight of armor. Nine 

 of the British dreadnaughts had protection to 

 the main deck only, while all of the German 

 dreadnaughts had side armor to the upper 

 deck. The Germans had a delay action fuse 



