3 
PRECIS 
AND 
TRANSLATIONS: 
“ REVISTA DI ARTIGLIERA E GENIO.” 
AN APPARATUS FOR CHECKING RECOIL. 
TRANSLATED BY 
CAPTAIN R. M. B. F. KELLY, R.A. 
The Mittheilung iiber gegenstcinde des Artillerie-und Genie- Wesens contains a 
notice of two different apparatus for checking the recoil of guns, of recent in¬ 
vention, one of which is due to the French Captain De Place, and the other to 
Signor Nottbeck, of Finland. They are both based on the same principle, viz., 
the utilisation of the expansion of the gases issuing from the muzzle on discharge. 
In accordance with an Admiralty order, Captain De Place’s apparatus has re¬ 
cently been tried with a field gun of 80 mm (3T"), and noteworthy results were 
obtained. 
The apparatus consists of a cap A (Fig. l a ) of plates of steel 8 mm (*31") thick, 
the concave side being towards the muzzle, it is continued towards the rear by a 
cylinder having a diameter of 40 cm (15*75''). This cap is rigidly attached by 3 
solid bolts B to a ring shrunk on to the chase of the piece. A central aperture D 
allows of the passage of the projectile, with a small amount of play (5 mm = *197" 
for a projectile 80 mm diameter). 
Fig. l a 
jL 
During the time that it takes for the projectile to traverse the length of the 
bore, the recoil is developed in accordance with the same laws that would control 
it if the apparatus were not there. The projectile then having left the bore, 
moves forward through the aperture in the cap, it is followed by the powder gas, 
which after leaving the bore tends to expand in all directions: the central portion 
has free passage through the aperture, the remainder is held by the cap and pro¬ 
jected backwards with great violence, the consequence being that the cap and 
hence the gun is subject to a force acting in the opposite direction to the force of 
recoil. 
3. VOL. XIX. 
I 8a 
