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by the person who is being tested, and using an opera glass, 
note the greatest distance at which he can distinguish with 
certainty the two positions of the 1-inch square. The object 
of the larger and of the smaller card is partly to discover that 
distance quickly, and partly to serve as a check against the 
man’s apparent power of distinguishing the positions being 
due to lucky guesses. The cards must hang truly, and this 
will be the more easily ensured if weights are attached to 
holes in their lower ends. 
The testing must be performed when the light is perfectly 
good, but not dazzling. Always test yourself when you are 
testing others, because if your own efficiency comes up to its 
normal standard, it is fair evidence that the conditions of 
light, &c., are normal also, otherwise very probably they are 
not. 
F. G. 
(b.) Hearing . 
Hearing may be roughly tested by the ability to hear 
words spoken or the ticking of a watch. 
Test hy words in speaking .—The subject should hold his 
head straight and have his mouth closed. The observer places 
himself first behind then at either side of the subject, taking 
care that his face is not seen by the latter, who should repeat 
the words spoken. The hearing should be tested first with 
both ears open, the observer being behind. The subject 
then stops up one ear with his finger and listens to the 
observer, who now places himself opposite and rather behind 
the clear ear, which he proceeds to test. The same plan is 
followed for the other ear. The observer should begin by 
testing the subject with single words such as “tip,” “fish,” 
&c., containing soft vowels and little emphasized consonants, 
such words being the most difficult to hear. The test words 
should be spoken in a loud whisper and the distance from 
which they are heard with both ears, and then by each ear 
alternately, should be recorded. The observer should stand 
