FOREST AND STREAM 
9 
How Science Can Increase the Efficiency of the Marksman 
A Suggestion for Making Army Marksmen of Citizen Shoooters 
By John A. Donovan, M. D. 
Member of the National Champion Indoor League Team of the Rocky Mountain Rifle Club 
T HE time has come when the efficiency of our 
army and navy depends on our marks¬ 
manship. Since Congress authorized the 
sale of small arms to any citizen affiliated with 
the National Rifle Association, everywhere an 
increasing interest is taken in this line of sport. 
Even our high schools are producing many ex¬ 
pert marksmen. 
Has the oculist kept pace with the increasing 
demands for his assistance with this work? The 
efficiency of our present military rifle is limited 
only by the ability of the man behind the gun, 
and the limitation of his vision is about the 
only restriction so far not overcome. 
At present, the official bull’s-eye at both 200 
and 300 yards is 8 inches in diameter, the shooter 
standing for the former and kneeling or sitting 
for the latter. All other ranges are shot from 
the prone position, i. e., the shooter lying flat 
on the ground, head toward the target. Twenty 
inches is the size of the bull’s-eye at 500 and 600 
yards, and for the expert who shoots the ex¬ 
treme ranges of 800 to 1,000 yards, 36-inch bull’s- 
eye is used. 
Using Snellen’s standard at an angle of 1 ft. 
we get a little more than 1 inch for each 100 
yards. Thus the 8-inch at 200=an angle of 4 ft., 
the same at 300 yards=2.66 ft., 20-inch at 500= 
4 ft., at 600=3.33 ft-, the 36-inch bull at 800=4.5 
ft.; at 1,000 yards it is 3.6 ft. From this it is easy 
to calculate the visual requirements from Snel¬ 
len’s test-letters that will enable a man to see 
a bull’s-eye distinctly at 1,000 yards, providing 
atmospheric conditions are correct. But as a 
bull’s-eye is round—therefore a spot—and the 
distinctness of a spot depends rather on its il¬ 
lumination than its size, the color contrast, light 
and atmosphere must be considered in the test. 
Reflections from the white ground, sand or 
water, bright sky, sun in eyes, etc., may make 
the target invisible. 
How to overcome these obstacles is the ocu¬ 
list’s problem. The shooter must elevate his 
sights, should the target suddenly become cloud¬ 
ed, and vice versa, should it become bright. A 
glass that would maintain a more uniform light 
would largely obviate this and produce more 
accurate results. 
The expert marksman to-day must be a 
scientist, understand the laws of internal and 
external ballistics, the effects of wind, tempera¬ 
ture, light, mirage, barometer, hydrometer on 
the elevation and deflection of each shot fired. 
In addition to this, according to the visual law 
of 1 ft. angle an error of 10 inches in the 1,000 
yards is to be allowed for. At 500 yards dis¬ 
tance, a 6-foot man would be seen at an angle 
of 13 ft. 44 in., or 2.7 times Snellen’s require¬ 
ments. At this standard, if it were not for the 
obstruction of the atmosphere, a man could be 
discerned at 1,375 yards. 
Our military rifle, new Springfield model, is 
very accurate and effective at any of these ranges. 
In fact, is sighted up to 2,800 yards. The sights 
are 22.1254 inches apart and a movement ot 
the rear sight 1-150 inch=i ft. sight radius, 
which moves the bullet 1 inch on target for 
each 100 yards. Though 1-150 inch in movement 
is necessary for extreme accuracy, the unaided 
eye can discern but 1-100 inch. 
Our patients ask for glasses to see rear sight, 
front sight and target all at one time, and usual¬ 
ly attribute the defect in shooting to old age. 
What can be done? 
The rear sight when held close is 9 1-4 inches 
from the eye when firing, requiring 4.33 D. S. 
accommodation. The front sight 32 inches re¬ 
quires but 1.25 D. S. accommodation, while the 
target requires none if the eye is emmetropic. 
One theory, as taught by Surgeon-General Long- 
more, C. B., is that an alteration of accommoda¬ 
tion takes place in rapid succession in shoot¬ 
ing. Bouchart gives credit to Sulzer for solv¬ 
ing the problem by the theory of the continua¬ 
tion of retinal impressions (6-100 of a second) 
gained by seeing each sight and the target sep¬ 
arately. To add to this, he shows that the time 
necessary to send impressions of objects to the 
One of America’s Best and Most Popular Trap 
Shooters, Billy Foord of Wilmington, and 
Mrs. Billy, to Whom go all Trophies 
Won by Sir William. 
brain is augmented with the distance. This 
theory has much in its favor and seems to have 
gained many adherents. The length of a retinal 
impression depends on the illumination and size 
of the object. On the other hand, Greener, a 
British expert, says: “The sights, both being 
out of focus- i be to some extent blurred and 
must there -ue of shape and color best adapt¬ 
ed to irr the eye directed on the target.” 
Dr. W. L. Hudson, one of the world’s best 
experts, says: 
If the eye is focused on the bull’s-eye, the 
rear sight will be blurred very much, and per¬ 
haps the front sight may blur a trifle, but not 
sufficient to make it indistinct. Therefore, all 
that is necessary is to be certain that we see 
top of front sight through center of aperture, 
and after that we may disregard rear sight. 
Our War Department, in the books of instruc¬ 
tions, recognizes the same facts. Their advice 
is to look at what one is shooting and not think 
of the sights. I have tested this theory by sus¬ 
pending my accommodation with homatropin, 
being then able to make the same scores. 
Experience has shown that those who shoot 
with both eyes open have much less strain on 
the eyes and can maintain a clear bull’s-eye 
which otherwise would become blurred. 
The best argument in favor of the theory of 
the necessity of accommodation in focusing the 
sights instead of the target is made by Maj. 
Henry A. Shaw, Surgeon LTnited States Army, 
and Lieut. Col. J. M. Banister, Department of 
Surgeon-General, United States Army. They 
quote several noted authorities, and with ten 
sharp shooters made many careful tests, firing 
five shots each with naked eye, five each with 
vision blurred by x lenses to make it 20-40, and 
five each vision blurred to 20-70. 
The results showed equally good. From this, 
they prove that an accurate focus of the sights 
only is necessary. They do not take into account 
that once the expert finds the bull’s-eye and is hold¬ 
ing good, he can make each successive shot come 
near the other as long as he retains his fixed 
position. Nor do they consider that the bull’s- 
eye is a spot; thus its distinctness depends on 
its illumination, and the law applicable to Snel¬ 
len’s test-type would not bear the exact relation. 
Above I have shown that the bull’s-eye has 
sufficient size to be easily discernible by a man 
with at least one-third normal vision. In fact, 
all that such a test really did accomplish was 
equivalent to shooting at a poorly colored target 
or in a bad light, which, as a matter of choice, 
no man would make. If accommodation is neces¬ 
sary, why do we find it so much less tiresome 
and the bulls-eye often more distinct when both 
eyes are kept open? 
If we are using accommodation, then we must 
suspend our convergence. Why does a sports¬ 
man choose the aperture and gold bead for use 
