2 
POPULAR SCIENCE REVIEW. 
what loss of velocity would be effected by the resistance of the 
air upon its reaching an iron-clad vessel a mile distant ? 
To fire cannon-balls with a given charge and ascertain their 
time of flight and range, or perhaps their penetrating power 
at short ranges ; and to “ time ” the fuze of a bursting charge, 
were the chief points formerly attended to. 
Attempts had been made, indeed, with considerable success, 
to ascertain one velocity for each ball striking a ballistic pen- 
dulum, which, upon receiving the shock of the striking ball, 
vibrated through a measurable arc. 
Even this solution was sufficiently difficult to have engaged 
the powers of Robins , Hutton , Didion , and Helie . So late 
as 1865 the latter confesses (“ Traite de Balistique ”) : “ Les 
solutions les plus avancees laissent encore fort d desirer . 
L' expose de ce qui a ete fait montrera du moins ce quHl reste d 
faire” (p. 2). 
There still remains, however, a great desideratum — a com- 
plete system which shall enable the scientific artillerist to 
answer any question respecting the motion and behaviour of a 
shot after it has left the cannon's mouth at any point of its 
path . Such results should also be immediately practicable by 
those who are without the scientific knowledge on which such 
results have been obtained. “ Applied science,” the master 
idea of the age, would, in the case of artillery students, 
receive a striking illustration : and thus literally connect the . 
Government with technical education. The general reader will 
understand the remarkable difficulties encountered in prose- 
cuting this research, by presenting to him a short resume of 
the history of this engrossing question. 
Nearly the whole system of theoretic modern gunnery is 
founded on Hutton’s “Mathematical Course” (H. died 1807). 
Hutton’s celebrated experiments with the ballistic pendulum 
were published by the Royal Society in their Transactions in 
1778, nearly one hundred years ago: these experiments had 
an important influence.* 
* Several European Governments took up the question. The chief 
theatre of them was Metz in 1839-40, where an extensive system was deve- 
loped under the direction of MM. Piobert, Morin, and Didion, with a large 
instrument constructed on the English plan. In 1855, a large ballistic pen- 
dulum was constructed at Elswick for the English government, at the cost 
of several thousand pounds, which has not hitherto been even used, for 
shortly afterwards Navez’s electro-ballistic instrument was imported from 
Belgium, which appeared to give correct initial velocities. But when the 
mathematicians began to cross-question its results, they found that no law of 
resistance of the air at various points of the ball’s path could be deduced 
from its use. Since 1866 Benton’s electro -ballistic machine with two pen- 
