344 
ITALIAN PERCUSSION FUZE, 
Through the bottom is pierced a hole, over this is a disc of wax cloth, 
then one of thin paper, and then a disc of sheet-brass pierced with a 
hole, corresponding to that in the bottom of case. These discs are 
held together by three rivets. 
II. The cylindrical box is of brass; it is bored axially, but its 
interior diameter is not the same throughout. It is screwed into the 
upper part of outer case, and, is itself closed by a screw stopper. In 
the upper part of it, where its diameter is greatest, is a ledge, on which 
is placed a ring, on which rest four feathers supporting the case con¬ 
taining the detonator. At that point of change of the diameter of the 
interior which is nearest the bottom of the box, a leaden ring is fixed 
in a groove, cut to receive it. 
III. The spiral stop is a helix of rough brass wire, which supports 
the weighted needle, during the time of flight of the shell. 
IY. The detonating needle is attached to a brass cylinder which is 
pierced axially. 
The case containing the cap with detonating composition, is of brass, 
having a brass screw stopper. The upper part of the case is cup¬ 
shaped, and fixed in this, by the stopper, is a ring with four feathers, 
on which the case is supported. At the bottom of the case is a small 
lead ring. 
The cap composition consists of five parts of chlorate of soda, two 
parts of fulminate of mercury, and five parts of sulphide of antimony; 
of this composition, about *28 to *3 of a gramme is placed in a tin cap, 
enclosed in one of copper, which is placed in the case, so that the tin 
cap rests on the small lead ring. The ring with the feathers is then 
placed in the cup-shaped top of the case, and the stopper screwed in. 
Lastly, the ring for supporting the cross feathers is placed on the 
uppermost ledge in the cylindrical box, the case with detonator placed 
thereon, and the cover of the box screwed on. 
The action of the fuze is as follows :— 
On the shock of discharge, the feathers being bent upwards, the case 
containing detonator slides down and lodges on the leaden ring at the 
bottom of the cylindrical box, so that the cap projects through the 
bottom of this latter. The needle is, however, prevented from striking 
the cap by the spiral stop. When the shell strikes the object, the 
weighted needle crushes the brass helix and the fuze is fired. 
