18 
ference of the imagination.—Note the greatest distance at 
which the watch can he heard. 
Touch .—Apply the points of an ordinary mathematical com¬ 
pass to different parts of the body, varying the interspace between 
them so as to ascertain the minimum distance, for each part of 
the surface tried, at which the two points cease to be felt as one. 
Smell .—For this no positive rules can be given.—Note 
whether any particular odours are disliked or enj oyed. Can they 
distingnish individuals in the dark by smell, as is said to be the 
case with some races ? Can fires be smelt at great distances P 
1. At what distance can a man count the test-dots in con¬ 
formity with the instructions on that head ? The following 
questions may also be answered (but due allowance must be 
made for the state of the atmosphere, colour of object and 
background; and too much reliance must not be placed on the 
answers as a means of comparison with similar observations 
made in distant countries :—2. At what distance can he di¬ 
stinguish the form of a human figure moving ? 3. At what 
distance can he distinguish a horseman. 
Dots for Testing Eyesight. 
The following are the test-dots employed for testing the 
sight of recruits in the British Army:— 
Each test-dot is 1 inch square, and corresponds at a distance 
of 15 feet with the bull’s-eye 2 feet square at 600 yards ; re¬ 
quired to be distinctly seen by every acceptable recruit. 
With perfectly acute vision these test-dots ought to be 
clearly visible in full daylight at 19 yards. 
Directions for using the Test-dots. 
1. Measure off’ 15 feet with precision. 
2. Hold the test-dot card or paper perfectly upright in front 
of the man, and let it face the light so as to he fully illuminated. 
3. Expose some of the dots (not more than seven or eight at a 
time) by covering the remainder with a card or a piece of paper, 
and desire the man to name their number and relative positions. 
4. Vary the groups frequently to provide against deception; 
by using a covering card with a square portion cut out of one 
corner, six different groups of dots may be exposed without 
exceeding the number of dots above mentioned. The test-dots 
should be kept perfectly clean. 
Thomas Longmore, D.I.Gl., 
Professor of Military Surgery. 
