150 VITALITY AND EFFICIENCY WITH KESTRICTED DIET. 



On the three mornings when walking experiments were made, i. e., 

 January 6 and 28 and February 3, the morning psychological program 

 was omitted, with the exception of strength of grip. This was taken 

 after 5 minutes of sitting following the walking on the treadmill. The 

 regular morning measurements were also omitted on December 20, 

 when the time was given over to taking standard electrocardiograms. 

 (See p. 393.) 



A detailed description of the technique and procedure for the meas- 

 urements used by the individual method is given in the following 

 pages. The measurements are numbered serially, as on page 139, and 

 treated in an order which represents their general increasing complexity. 



(6) Strength of Grip. 



The instrument commonly known as ''improved form of Smedley's 

 dynamometer" was used in this test.^ The handles of the instrument 

 were adjusted to a span of 5.5 cm. and were kept constant at this 

 distance with all the subjects. The subjects as a group and individu- 

 ally were given full instructions in the use of the dynamometer. They 

 stood erect and free from other support; the instrument was held down 

 at the side of the thigh, not against the leg, and dial outward.^ Five 

 trials were made with each hand alternately. There was an interval 

 of about 10 seconds between trials, during which the assistant read the 

 instrument and set the indicating hand at zero. Immediately after 

 the grip the subject called ''right" or "left," as the case might be, and 

 held out the instrument to the assistant to be read. The assistant did 

 not call out the reading, but entered it in a form provided for the pur- 

 pose. No particular effort was made to stimulate the subject, although 

 before he began he was told to do his best. Usually someone else be- 

 sides the assistant was present and watching him. Although no oppor- 

 tunity was given the subject to read the record on the dial carefully, he 

 knew in a general way, from the position of the indicator, about what 

 score he was making, and might be able to remember his performance 

 from time to time, but no information was given him. 



The particular instrument which was used was tested against stand- 

 ard weights to find if any corrections should be made in the reading.^ 

 The results of these standard tests are shown in table 8. Two sets of 

 readings were taken, that is, under temperature conditions of 25° C. 

 and 13.5° C. The table is divided accordingly; there is a column for 

 standard weights; one for the average reading from five entirely inde- 

 pendent trials, and the average error, plus or minus, between the read- 



^ This instrument is manufactured by C. H. Stoelting Co., Chicago. The particular one em- 

 ployed belonged to the Massachusetts State Psychopathic Hospital, Boston, and was 

 kindly loaned to us for the period of the experiment. 



^ See Whipple, Manual of Mental and Physical Tests, part 1, Baltimore, 1914, p. 100, for 

 standard recommendation of procedure. The men were asked to remove any rings 

 from their fingers during the test. 



3 Kohs, Journ. Exp. Psychol., 1917, 2, pp. 304 ff. 



