315
NEW EXPERIMENTS
TRACT 34-.
N°. 5 was more expressly to show the effect of differentlengths of the same gun : and for this purpose, it was to befired a sufficient number of rounds with its whole length ;and then to be successively diminished, by sawing off it 6or 12 inches at a time, till it should be all cut away : firinga number of rounds with it at each length. And for theconvenience of suspending this gun near its centre of gra-vity, for all the different lengths of it, a long thin slip wascast with it, extending along the under side of it, from thebreech to almost the middle of its length. By perforatingthis slip through with holes immediately under the centreof gravity for each length, after being cut, a bolt was topass through the hole, on which the gun might be sus-pended. The other guns were slung by their trunnions.The exact weight and dimensions of all these guns areexhibited in the following table.
No. ofthe gun
Length of the
Diameteratthe
Diain.
of thebore
Weight
Piece, in
Bore
, in
breech
muzzle
calib.
inch
calib.
inch
inch
inch
inch
Jb.
i
15
30-3
14-12
28-53
7*85
6-88
2-02
290
2
19-98
40-35
19-02
38-43
7-43
5-92
2-02
289
3
29-2
60
28-56
57-10
6-73
4-68
2-02
295
4
41-04
82-9
39-50
80-23
6-1
4-31
2-02
378
5
40-S4
82-5
40-00
80-80
6-47
4
2-02
502
12. As these guns were to be slung by their trunnions, toobserve the relation between the velocity of the ball and thearch of recoil described by the gun, vibrating on an axis,certain leaden weights were cast, to fit on very exactlyabout the trunnions of the gun, to render it so heavy, asthat the arcli of recoil might not be inconveniently great.These consisted, first of central pieces to fit the trunnions,and then over them cylindrical rings of different sizes, bothturned to fit exactly ; the whole being held firmly togetherby iron bolts put into holes bored through all the pieces.Ihese were also of different sizes, so as to bring all theguns exactly up to the same weight; the whole weight of