138 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



to many irregularities. All of the men in one squad could thus be 

 measured on one day within a period of 4 hours and following the 

 ingestion of a standard meal which was uniform for each time they 

 were present. (See p. 262.) Physical activity during the hours preced- 

 ing the evening session was also made uniform by the necessity of 

 the railroad journey from Springfield to Boston. 



At the Nutrition Laboratory certain apparatus and techniques were 

 available which, under the circumstances, could not well have been 

 transferred to Springfield. Early in September, as has been explained 

 previously (see p. 44), there was considerable doubt as to the possi- 

 bilities in the experiment. The enrollment at the college was small 

 and many of the older students would probably be called for Govern- 

 ment service. It was of course impossible to know whether the stu- 

 dents would volunteer as subjects, and, if so, how many would be 

 available for the experiment. Furthermore, as in the preliminary 

 plans it was thought desirable to continue the experiment only to the 

 Christmas vacation, it was necessary that when college did open, the 

 experiment, if it was to be started, should begin immediately. ^ By 

 coming to the Nutrition Laboratory for the psychological measure- 

 ments the greater part of the apparatus would be in readiness and thus 

 a minimum of experimental opportunity would be lost. Some of the 

 apparatus and technique had been previously elaborated in connection 

 with other problems with the object of securing measurements and 

 procedures which could be repeated on the same individual without 

 the development of large practice changes. Great care had been taken 

 to make the measurements as objective and free from personal bias as 

 possible. Many of them will be noted to have a distinct physiological 

 trend. The avoidance of all practice changes with fluctuations in 

 interest and attention is of course an ideal which is never quite reached 

 in psychological investigations, but it is believed that the measure- 

 ments, procedures, and conditions in the present research all contributed 

 to minimizing the influence of these factors. The interval of two 

 weeks which came between experimental sessions of the same squad 

 was also useful for this purpose. 



In planning this phase of the investigation there were several con- 

 siderations which favored the use of a wide range of neuro-muscular 

 measurements. The nature and extent of the effects of prolonged 

 reduced diet could not be anticipated, and for this reason these effects 

 should be given as many opportunities as practicable to show them- 

 selves. Our men were not what might be termed trained psychological 

 subjects; they had received but slight practice in introspection. The 

 tests were given in the evening. Under these conditions prolonged 

 measurements of one kind would have favored development of sleepi- 

 ness and fatigue. The physical movements and frequent changes 

 necessitated by the large variety of measurements prevented ennui. 



