PSYCHOLOGICAL PROGRAM AND TECHNIQUE. 



147 



a great help in steadying the subject and giving him a feeling of sure- 

 ness, so this interval was retained. The pairs were regularly given in 

 order of difficulty, i. e., proceeding from S-8 to S-1, and the judgments 

 were marked in sequence on horizontal lines in the blank forms. Thus : 

 S-8 was marked in square A-1, and S-1 in square E-1. Thirty judg- 

 ments with each interval or 150 judgments in all constituted the test. 

 After 100 of the pitch-discrimination judgments had been given, a 

 short intermission was taken, during which the subjects made a pulse 

 count on themselves, recording the same on the back of the pitch- 

 discrimination blank. Immediately after the last pitch-discrimination 

 judgment had been made, the blanks, which had been dated, and 

 signed, were collected and the men were assigned to their next duties. 



Fig. 2L — A portion of a pitch discrimination record. 



Each square filled in with H or L represents a judgment on a pair of tones. Sometimes the subject 

 was in error, as is indicated by the diagonal lines. In columns A and G the tones presented 

 were S-8. This was the easiest pair to judge. The most difficult pair was S-1 (see columns 

 E and K). 



MEASUREMENTS BY THE INDIVIDUAL METHOD. 



The pitch-discrimination test was the last test in the group series. 

 At its conclusion, and after the measurement of the skin temperature 

 (see p. 249), four of the men were sent downstairs for individual 

 psychological measurements. The remaining subjects were employed 

 for the Du Bois body measurements, the blood test, practice in be- 

 coming used to walking on the treadmill, etc. (see program as outlined 

 on p. 59), until the experimenters were to use them. 



The psychological apparatus was distributed in three rooms, which 

 open from a common hallway. With the aid of two assistants, it 

 was possible to make such measurements with four of our subjects at 

 the same time, each man serving a total of about 70 minutes. The 

 measurements were grouped in the different rooms, according to expe- 

 diency. In room A were located Nos. 6, 11, 16, and 17 (strength of 



