78 
MINUTES OF PROCEEDINGS OF 
These coverings of gut skin, silk and varnish, not only diminish the 
sensibility of the ball to the point requisite to secure it against premature 
explosions, 1 2 but they also effectually protect the detonating composition from 
damp. 3 
The ball rests with its lower or conical projection in the fire hole of the 
cone plug; the upper or cylindrical projection entering a hole in the steady 
plug- 
The Steady Ting (Tig. 1, gg) is a cylindrical plug of the same alloy as 
the ball and cone plug, exactly fitting the interior of the fuze. A hole is 
drilled through the vertical axis of the plug, not to serve as a fire hole but 
for the admission of the upper projection of the ball. The top side of the 
plug is slightly hollowed out. 3 
The steady plug occupies a position in the fuze immediately underneath 
the top plug and immediately over the ball. 
When the fuze has been placed together with the several plugs and parts 
occupying the positions described, the key hole in the top plug and the cross 
cut in the bottom plug are filled with shellac putty, and discs of fine paper 4 
are secured over the top and bottom of the fuze 5 with shellac varnish, the 
better and more completely to exclude moisture. A leather collar is secured 
by shellac varnish to the under part of the shoulder of the fuze. 
The number of thousand of the fuze, the year and month of issue and a 
Roman numeral I (for Pattern I) are stamped on the top of the fuze 6 
between the wrench holes. The whole of the exterior of the fuze is lacquered. 
Action . 
These fuzes require no preparation. Their action is as follows:—The 
shock of the discharge crushes up the lead cup, 7 a result which is due 
partly to its own inertia, and partly to that of the cone plug, ball and steady 
plug which rest upon it. 8 
1 Such as would probably result from the friction of the ball, if the composition were naked, 
against the inside of the fuze during the flight of the shell, or on the first shock of discharge. 
2 Pettman’s fuzes are therefore little, if at all, sensible to the effects of damp, as independently 
of the protection afforded by the covering of the ball, the fuze itself is securely closed, and the ball, 
the only part liable to deterioration, is thus doubly protected. 
3 The only object of this hollowing out is to remove the “burr” which is necessarily thrown up 
by the drilling of the hole and which would prevent the steady and top plugs from coming into 
close contact. 
4 Tracing paper. 
5 Over the whole of each end, the paper is subsequently broken at the four wrench holes. 
6 The Pettman’s fuzes were always stamped with the number of thousand, this mark therefore 
indicates the actual number made up to a particular date, whereas the stamping with the number 
of thousand was not adopted for other fuzes until 1864; nor was the system of stamping 
these fuzes with the date (in addition to the number of thousand) adopted until that year; the 
system of stamping the No. of the Pattern was not adopted until 1866. 
7 See what has been said, p. 77, note 1, respecting the importance of the cups being of one 
uniform strength, otherwise the required action may not take place. 
8 The importance of keeping the hall within strict limits as to weight will now be apparent, for 
evidently any increase in its weight will tend to cause the crushing of the lead cup under lighter 
shocks than that of the discharge of the gun and will tend therefore to make the fuze less safe ; 
while any decrease in their weight entails the possibility of the non-crushing of the lead cup and 
