202 



NATURE 



[October 21, 19 15 



Txalles systems. They give also the correspond- 

 ing indications of the hydrometers used in Russia, 

 Holland, Spain, and Switzerland.. 



All the tables are well arranged, well printed, 

 and well spaced, with figures in large type: this 

 all makes for accuracy and convenience in use. 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



Rule for Determining Direction of Precessional 

 Movement. 



The method of determining the sense of the pre- 

 cession is usually given in the following way: — "If 

 the axis of angular momentum and the torque axis are 

 drawn in the same sense (that is, for the same direc- 

 tion of turning), then the axis of angular momentum 

 sets itself towards the torque axis." 



By this method we must imagine the axis of rotation 

 and torque, which cannot be seen directly. By the 

 following method this is not necessary : — 



" If you stand at one end of the axle of the gyro- 

 scope, it will precess in the same sense to the rotation 

 of the wheel, as seen by yourself." Here, the moment 

 of force due to your own weight determines the tilting 

 couple. According to my experience, this is a very 

 convenient and practical rule for the direction of pre- 

 cession of a gyroscope. W. Watanabe. 



34 Waldegrave Park, Twickenham, September 28. 



I AM obliged by your courtesy in allowing me to see 

 Prof. Watanabe 's communication. He sent me his 

 rule some little time ago, but by an accident which I 

 regret his letter did not receive immediate attention. 



I take it that what Prof. Watanabe 's very concise 

 statement suggests is the following. Imagine the 

 gyrostat, supported, let us say, at a point on its axis 

 of symmetry, with that axis inclined at an angle 6 to 

 the upward vertical, and precessing under a couple 

 produced by a gravity force applied at a point on the 

 axis of symmetry. If that force be due to the weight 

 of an observer standing on the axle and looking to- 

 wards the spinning flywheel, the axle, with the ob- 

 server,^ will be carried round in azimuth in the direction 

 in which he sees the part of the wheel looked at 

 carried by the rotation. 



This is quite correct and convenient if it Is the upper 

 part of the wheel that is looked at, and if the precession 

 is, as it is almost always taken to be, and usuallv is, 

 that given by the numerically smaller root of the quad- 

 ratic equation which determines the steady motion of 

 the gyrostat for a given value of (9. But, except in 

 the case of 0-go°, when the larger root is infinite, it 

 is possible, by properly starting the gyrostat, to realise 

 the precession given by the numerically larger root. 

 This is the "adynamic" precession, so called because 

 to a first rough approximation, this precession, if the 

 gyrostat Is rapidly rotating, is independent of the 

 applied couple. In this case, when also. 6 Is greater 

 than 90°, and the roots are therefore opposite In sign, 

 Prof. Watanabe's rule must be reversed. But it is 

 to be noted also that. In these unusual circumstances, 

 neither does the rule hold that the axis of spin follows 

 the couple axis. A. Gray. 



The University, Glasgow, October 7, 

 NO. 2399, VOL. 



The Meaning of " Chincough." * J 



In the notice (Nature, October 7, p. 141) of thej 

 book, "A Chaplet of Herbs," the expression "chin- 

 cough" Is explained in parenthesis as " (hiccough). 

 The word is in everyday use in this country, and never^ 

 in any other sense than the whooping-cough ; 

 etymology being understood as connected with the, 

 French chien = a. dog. 



The popularly recognised cure for hiccup in children 

 used to be, and may be still, to "frighten it away" 

 by some sudden and discomposing question. It often 

 proved to be quite efficacious. W. E. Hart. 



Kilderry, Londonderry, Ireland, October 10. 



96] 



FELLOWSHIPS FOR INDUSTRIAL 

 RESEARCH.^ 

 nPHE subject of the pamphlet referred to below 

 -^ is one of first-rate importance, especially at 

 the present time of crisis in certain branches of 

 manufacture, the cause of which has been attri- 

 buted to failure to link science and industry. 



The experiment referred to is one devised by 

 the late Prof. Duncan, of the University of Kansas 

 (and later of Pittsburgh). It begins by insisting 

 that technical training should not cut into the full 

 graduate course in pure science. The failure to 

 co-ordinate academic training with industrial 

 methods is attributed to mistakes on both sides. 

 It is urged on the side of industry that current 

 industrial practice is always ahead of text-book 

 presentation, that academic methods are too 

 minute and cumbersome, and that whilst strict 

 scientific accuracy is essential in a pre-graduate 

 course, it must give place to less accurate time- 

 saving processes in the factory. 



The university professor is also accused of re- 

 garding the utilisation of science for human needs 

 as more or less degrading to science itself, and 

 that in consequence he is careless in selecting a 

 chemist possessing the right qualifications ; for as 

 Dr. Duncan asserts, industrial research demands 

 all the qualities which are necessary for success 

 in pure science, together with ability to control 

 workmen. 



The case against industry is much more search- 

 ing. Dr. Duncan considers that the failure on the 

 part of the factory to appreciate the advantage 

 of applied science is due to an incapacity to select 

 chemists, inexperience in dealing with them, and 

 ignorance of the facilities in the way of labora- 

 tories and libraries which should be placed at their 

 disposal. He states that he has met with instances 

 of chemists of high training, creative power, and 

 practical character who are overburdened with 

 routine drudgery and subjected to the interference 

 of factory foremen, and are working under an 

 entire misapprehension on the part of the officials 

 of the company as to their possibilities and value. 

 Moreover, it is pointed out that the manufacturer 

 may not know the real nature of the problems 

 which have to be solved, their relative import- 

 ance, or the kind of knowledge required for their 

 solution. He has no means of judging the quali- 

 fications of the men available for his researches 



1 "An Experiment in Industrial Research." By T. L. Humberstone. 

 Board of Education : Educational Pamphlets, No. 30. [(London : Wyman 

 and Sons, Ltd.) Price ^d. 



