July 29, 1920] 



NATURE 



^7Z 



the accuracy of Ptolemy's latitude and longitude; 

 therefore it must be the declination that was in 

 error; this, he thinks, was extrapolated from the 

 declinations observed by Timocharis and Hippar- 

 chus, and he concludes that Ptolemy observed no 

 declinations at all, but merely deduced them from 

 Timocharis and Hipparchus. This probably sug- 

 gested to Tycho Brahe the more sweeping charge, 

 adumbrated in his " Progymnasmata " ("Opera," 

 ii., 151), and stated clearly in the introduction to 

 his Catalogue ("Opera," iii., 335), that the whole 

 of Ptolemy's Catalogue was merely a reproduction 

 of the Catalogue of Hipparchus, reduced to 

 Ptolemy's epoch by means of a constant correction 

 to the star places. This charge has had a wide 

 currency, but has been refuted by Laplace and 

 Ideler, and finally by Dr. Dreyer in his paper, 

 "On the Origin of Ptolemy's Catalogue of Stars," 

 Monthly Notices of the Royal Astronomical 

 Society, Ixxviii. (1918), pp. 343-49. The absurdity 

 of Rothmann's original charge may be shown by 

 a computation of the position of Regulus for the 

 epoch of Ptolemy's tables. Ptolemy's declination, 

 as it happens, is correct, but his latitude is in 

 error, and his longitude is greatly in error, doubt- 

 less because his tables gave a false longitude to 

 the sun, with which Regulus was compared. 



J. K. FOTHERINGHAM. 



Psychological Tests in Industry. 



Employment Psychology: The Application of 

 Scientific Methods to the Selection, Training, 

 and Grading of Employees. By Dr. Henry C. 

 Link. Pp. xii + 440. (New York : The Mac- 

 millan Co.; London: Macmillan and Co., Ltd., 

 1919.) Price los. 6d. net. 



EXPERIMENTAL psychologists in this country 

 have always been keenly interested in re- 

 search into individual mental differences, but to 

 America we must turn for the first attempts to 

 apply psychological tests to vocational selection 

 and guidance. As might have been expected, an 

 alternative method has arisen which claims to 

 judge special abilities, aptitudes, and characters 

 by the methods of phrenology, the colour of 

 the hair and eyes, the texture of the skin, the 

 slope of the handwriting, the squareness or round- 

 ness of the face, the shape of the chin, etc. As 

 Dr. Link points out, attempts have been made 

 to transform this method into "a reliable and 

 scientific method of character analysis. . . . This 

 so-called science has received wide publicity and 

 has been accepted [both in America and in this 

 country] by many prominent and hard-headed 

 business men. It attempts to place observation 

 NO. 2648, VOL. 105] 



on a scientific basis by assuming that certain ob- 

 servable physical characteristics are identified with 

 certain definite mental qualities, and by asserting 

 as a corollary that a visual observation and 

 measurement of the physical characteristics enable 

 the observer to gauge a person's mental, moral, 

 and emotional qualities. The smattering of scien- 

 tific phraseology in the presentation of this 

 method is just sufficient to impress those who have 

 only a superficial knowledge of the scientific facts 

 involved. . . . The fundamental assumption on 

 which the so-called science of observation rests 

 is an assumption entirely unwarranted by the 

 facts " (pp. 240, 241). 



Contrast with this the methods of industrial 

 psychology. The psychologist first "finds, by 

 means of an experimental process, what the rele- 

 vant activities in an occupation or an operation 

 are." This he does by means of tests which are 

 tried out on workers whose ability is known and 

 with whose work success in the tests can be com- 

 pared and correlated. In this process he also dis- 

 covers the standard which ought to be reached in 

 the significant tests by those who wish to succeed 

 at the kind of work in question. He then stand- 

 ardises the manner in which these tests should be 

 used, so that every applicant for a particular kind 

 of work will be examined in exactly the same 

 way, and his ability determined according to the 

 same formula (p. 249). 



As Prof. Thorndike indicates in his introduc- 

 tion, "Dr. Link's book is important because it 

 gives an honest impartial account of the use of 

 psychological tests under working conditions in 

 a representative industry. He has the great merit 

 of writing as a man of science assessing his own 

 work, not as an enthusiast eager to make a 

 market for psychology with business men. In- 

 deed the story of his experiments is distinctly 

 conservative . . ." (p. x). They included the test- 

 ing of girls and men, of clerks, stenographers, 

 typists, and "comptometrists," of machine 

 operators, apprentice tool-makers, etc. They show 

 what a wealth of valuable information for voca- 

 tional guidance they can afford, and how excellent 

 a corrective they are to the vague, inaccurate know- 

 ledge too often possessed by the foreman of the 

 relative abilities of those who work under him. 

 The tests used are fully given in an appendix to 

 the book. The volume clearly indicates the im- 

 portance of employment psychology, alike to the 

 employer who "wishes to obtain the best pos- 

 sible kind of human material," and to Labour if 

 it "wishes to carry out collective bargaining, if it 

 wishes to base its claims for individuals on the 

 sound basis of ability and training " (p. 389). 



