Studies of fatigue.
85
to a large extent apparent. A gradual increase or continued varia¬
tion would be more easily explained than the rhythm which nature
seems to introduce. No cause for this phenomenon can be ascribed
to any known external conditions. Some of the notes made were :
“can scarcely see,” this was when looking at objects after the
experiment ; “ toward the last, the objects grew too dim,” the
power of convergence was greatly decreased ; “ focusing not clear,
especially toward the last ; ” “ hard to focus toward the last.” As
regards the right eye, which was not used, these notes were made :
Table V.
Fatigue in monocular estimate of depth.
Number of exper. __
i
2
3
4
5
6
7
8
9
10
Observer A ......
0
— 2
8
12
9
9
21
27
29
20
Observer B ......
. 0
1
-2
—7
-4
10
— 20
1
12
13
Observer C ........
0
9
19
26
36
44
51
43
52
54
Number of exper.-
. 11
12
13
14
15
16
17
18
19
20
Observer A ......
. .36
33
30
40
34
40
39
48
45
41
Observer B .......
-10
5
14
2
15
9
11
-3
-4
-3
Observer C______
. 65
63
79
10
69
66
74
64
61
71
Number of exper.
21
22
23
24
25
26
27
28
29
30
Observer A.....
50
62
54
53
55
54
59
60
48
65
Observer B.......
-11
8
1
7
21
19
14
5
1
22
Observer 0......
... 69
61
71
76
85
61
75
76
80
80
Number of exper.
31
32
33
34
35
36
37
38
39
40
Observer A._______
52
50
66
59
57
53
71
67
67
70
Observer B____
. + 7
14
-1
— 1
4
6
23
4
1
-12
Observer C.......
. 91
74
75
81
87
92
89
83
99
89
Number of exper___
. 41
42
43
44
45
46
47
48
49
50
Observer 0_______
.103
104
82
89
92
103
106
107
98
104
The numbers are positive unless otherwise designated.
“ right eye pained as much as the left ; ” “ right eye felt worse till
I got up, and then the left pained me very much.” There is little
doubt that jthe unused eye was accommodating and focusing with
the seeing eye. It might be claimed that much assistance may have
been received from its sensations of convergence. As its focus
depended on the seeing eye, it is not clear how it could give any aid,
although the claim that work with one eye is in reality nothing
more nor less than work with both eyes is undoubtedly correct.
The facts noted in this paragraph all refer to Observer A.
Table V also shows the relations of fifteen fatigue sets taken
upon Observer B. The result is very different from that just pre-