186 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



ond record, so that the tracings would not overlap sufficiently to make 

 them illegible. Two plates were taken for each subject, giving a total 

 of four series of movements. A plate from each of two subjects may be 

 seen in figure 52. The records are to be read from the bottom upward. 

 The subject's eye movements were along a horizontal line, the plate 

 moving downward at right angles to the line of eye movement. Right 

 and left indicated in figure 52 corresponds with R and L of figure 50. 

 They are of course reversed since the record was taken through a lens. 

 In beginning a series of movements the subject looked for an instant at 

 the right-hand mark R after it was exposed ; then the eye was moved 

 to L at the left. A corrective movement was frequently necessary to 

 direct the vision definitely at the fixation mark. The dashes between 

 the fixation-points were caused by the time-interrupter in the beam of 

 light, each dash and one interspace equaling 0.01 second. The cor- 

 rective movements in the record of the left-hand plate show that this 

 subject was unusually accurate in his fixation of the marks. The other 

 man sacrificed accuracy for speed. In spite of instructions the sub- 

 ject who made the records in the right-hand plate did not accurately 

 fixate the marks in turn. The difference can be clearly brought out 

 by laying a rule along the left-hand boundary of these records. The 

 fixation marks should fall on a straight line, which they closely 

 approximate in the left-hand records. 



(15) Speed of the Finger Movements. 



Finger-movement records were taken both evening and morning. 

 This test is a rather simple one to arrange and to perform, and it has 

 proved itself useful in earlier investigations at the Nutrition Laboratory.^ 

 The apparatus, method, and form of the record for this measurement is 

 readily understood from figure 53, which is a schematic representation 

 of a part of the apparatus shown in figure 31, page 160. The exposure 

 apparatus E (fig. 31) has been disconnected, undamped, and with- 

 drawn. The subject's hand clasps the post P; his arm is comfortably 

 supported at S. The lower part A of the lever system used for record- 

 ing the muscle- thickening of the patellar reflex is removed and a light, 

 adjustable, but rigid connection W is placed (fig. 53) between the metal 

 recording-point R and the finger at F. A small rubber band about 

 the finger between the first and second joints forms an easy connection 

 with W, which is adjustable in length, its longer portion being a very 

 light-weight wooden member for purposes of insulation from the high 

 tension sparks. 



The high tension terminals of a transformer T of commercial design 

 are connected with the frame of the kymograph and the metal recording- 

 point R. A suitable current (0.7 ampere) from a 1 10-volt D. C. source is 

 used on the low-tension side of the transformer. A contact C in this 



1 Dodge and Benedict, Carnegie Inst. Wash. Pub. No. 232, 1915, pp. 167 ff.; Miles, Carnegie 

 Inst. Wash. Pub. No. 266, 1918, p. 84. 



