403 
NOTES ON THE LAYING OF GUNS BY MEANS OF A TELESCOPE. 
BY 
COLONEL de COSSIGNY, 
TRANSLATED PROM THE FRENCH BY 
CAPTAIN E. WALSH, E. A. 
The long ranges at which it is often necessary to open fire, as well as 
the care taken by the enemy to mask his guns and his troops, do not 
always permit gunners to distinguish their object clearly, and the 
necessity for some optical apparatus in connection with the sights is 
daily becoming more and more pressing. 
In order to be convinced of this truth we need only observe how 
frequently battery commanders allow the Nos. 1, or “ layers,” to look 
through the battery telescope before proceeding to lay their guns. 
At ranges exceeding 2000 metres, if there is not a very strong 
light on the object, if the object does not stand out clearly on the 
horizon, or if the enemy's batteries and troops occupy ground cut up 
by hedges, &c., we can distinguish nothing with the naked eye, and our 
gunners must either lay their guns approximately in the required direc¬ 
tion, or on the smoke of the enemy's pieces, which is a very vague sort 
of mark. 
During the last grand manoeuvres executed by the 18th Corps, the 
battery commanders ascertained that even at ranges of 1500 metres it 
was impossible to distinguish the enemy's batteries when they were 
well placed. Besides, to enable a battery commander to find his range 
rapidly and surely, the first condition is that the six guns be not only 
laid on the same point, but also that they be laid in the same manner; 
now, in practice, some men always lay high, others always low. With 
the system which I propose, if all the instruments of the battery, or 
even of the regiment, are regulated by the same man, we can obtain 
an absolute regularity of fire. On the other hand, if we consider how 
difficult it is to find good “ layers," whose eyes do not soon become 
tired, we must admit the very great importance of having a means by 
which a man without any particular aptitude, and even with bad sight, 
can lay a gun at any range with mathematical exactitude. 
Before describing the instrument which I propose, it may be well to 
state the manner in which guns are laid with the tangent-scale and 
moveable sliding leaf, for it is partly on the arrangement of these sights 
that my system depends. 
The elevation having been given according to the estimated range— 
the altitude of the place, and the atmospheric conditions—and the 
deflection according to the tables of “ derivation," and with the proper 
allowance for the force and direction of the wind, the line of sight is 
directed on the object with more or less accuracy. The gun is then 
Ordinary 
sights insuf¬ 
ficient under 
certain con¬ 
ditions of 
modern 
warfare. 
Experience 
gained 
during 
recent 
manoeuvres. 
Importance 
of laying 
every gun in 
exactly the 
same 
manner. 
Uniformity 
and accu¬ 
racy in 
laying 
secured by 
the tele- 
scopic 
apparatus. 
Laying guns 
with the ser¬ 
vice sights. 
