The Scale following shows the Proportions of Gunpowder applicable under the foregoing Rules and Regulations to the Proof of the various Classes of Arms as distinguished by the Trade Numbers indicating the Calibre.

Number
of
Gauge.		Diameter
of
Bore
by
Calcu-
lation.		Diameter
of
Balls
for
Proof.		Weight
of Balls
for
Proof.		Charges of Powder for Proof.
First Class.Second Class.Third Class.Fourth Class.
Definitive
Proof.		Provisional
Proof.		Definitive
Proof.		Definitive
Proof.		Provisional
Proof.		Definitive
Proof.
inches.inches.grains.grains.ozs.drs.grains.ozs.drs.grains.ozs.drs.grains.ozs.drs.grains.ozs.drs.grains.ozs.drs.
11·6691·6496752481211...481211...240658 38508123⁄438508123⁄4240658
21·3251·3053342232455 232455 11622101⁄2185944 185944 11622101⁄2
31·1571·1072211153138 153138 766112 12252123⁄412252123⁄4766112
41·0521·03216491176211 1176211 588151⁄2941221⁄2941221⁄2588151⁄2
5·976·956131593022 93022 46511 7441111⁄47441111⁄446511
6·819·8991090766112 766112 383...14 612161⁄2612161⁄2383...14
7·873·85393165618 65618 328...12 525131⁄4525131⁄4328...12
8·835·81581260216 60216 301...11 481111⁄2481111⁄2301...11
9·803·78372049212 49212 246...9 394...141⁄2394...141⁄2246...9
10·775·75564646511 46511 232...81⁄2372...131⁄2372...131⁄2232...81⁄2
11·751·731586437...16 437...16 219...8 350...123⁄4350...123⁄4219...8
12·729·709535437...16 437...16 219...8 350...123⁄4350...123⁄4219...8
13·710·690493410...15 410...15 205...71⁄2328...12 328...12 205...71⁄2
14·693·673457383...14 383...14 191...7 306...111⁄4306...111⁄4191...7
15·677·657425383...14 383...14 191...7 306...111⁄4306...111⁄4191...7
16·662·642399369...131⁄2369...131⁄2185...63⁄4295...103⁄4295...103⁄4185...63⁄4
17·649·629374369...131⁄2369...131⁄2185...63⁄4295...103⁄4295...103⁄4185...63⁄4
18·637·617352342...121⁄2342...121⁄2171...61⁄4273...10 273...10 171...61⁄4
19·626·606334301...11 301...11 150...51⁄2241...83⁄4241...83⁄4150...51⁄2
20·615·595316273...10 273...10 137...5 219...8 219...8 137...5
21·605·585300273...10 273...10 137...5 219...8 219...8 137...5
22·596·576287246...9 246...9 123...41⁄2197...71⁄4197...71⁄4123...41⁄2
23·587·567274246...9 246...9 123...41⁄2197...71⁄4197...71⁄4123...41⁄2
24·579·559262232...81⁄2232...81⁄2116...41⁄4186...63⁄4186...63⁄4116...41⁄4
25·571·551251232...81⁄2232...81⁄2116...41⁄4186...63⁄4186...63⁄4116...41⁄4
26·563·543242232...81⁄2232...81⁄2116...41⁄4186...63⁄4186...63⁄4116...41⁄4
27·556·536231232...81⁄2232...81⁄2116...41⁄4186...63⁄4186...63⁄4116...41⁄4
28·550·530223232...81⁄2232...81⁄2116...41⁄4186...63⁄4186...63⁄4116...41⁄4
29·543·523214205...71⁄2205...71⁄2102...33⁄4164...6 164...6 102...33⁄4
30·537·517207205...71⁄2205...71⁄2102...33⁄4164...6 164...6 102...33⁄4
31·531·511—205...71⁄2205...71⁄2102...33⁄4164...6 164...6 102...33⁄4
32·526·506194205...71⁄2205...71⁄2102...33⁄4164...6 164...6 102...33⁄4
33·520·500—191...7 191...7 96...31⁄2153...51⁄2153...51⁄296...31⁄2
34·515·495182191...7 191...7 96...31⁄2153...51⁄2153...51⁄296...31⁄2
35·510·490—191...7 191...7 96...31⁄2153...51⁄2153...51⁄296...31⁄2
36·506·486172191...7 191...7 96...31⁄2153...51⁄2153...51⁄296...31⁄2
37·501·481—191...7 191...7 96...31⁄2153...51⁄2153...51⁄296...31⁄2
38·497·477162178...61⁄2178...61⁄289...31⁄4142...51⁄4142...51⁄489...31⁄4
39·492·472—178...61⁄2178...61⁄289...31⁄4142...51⁄4142...51⁄489...31⁄4
40·488·468154178...61⁄2178...61⁄289...31⁄4142...51⁄4142...51⁄489...31⁄4
41·484·464—164...6 164...6 82...3 131...43⁄4131...43⁄482...3
42·480·460146164...6 164...6 82...3 131...43⁄4131...43⁄482...3
43·476·456—164...6 164...6 82...3 131...43⁄4131...43⁄482...3
44·473·453139164...6 164...6 82...3 131...43⁄4131...43⁄482...3
45·469·449—150...51⁄2150...51⁄275...23⁄4120...41⁄2120...41⁄275...23⁄4
46·466·446133150...51⁄2150...51⁄275...23⁄4120...41⁄2120...41⁄275...23⁄4
47·463·443—150...51⁄2150...51⁄275...23⁄4120...41⁄2120...41⁄275...23⁄4
48·459·439127150...51⁄2150...51⁄275...23⁄4120...41⁄2120...41⁄275...23⁄4
49·456·436—150...51⁄2150...51⁄275...23⁄4120...41⁄2120...41⁄275...23⁄4
50·453·433122150...51⁄2150...51⁄275...23⁄4120...41⁄2120...41⁄275...23⁄4
Number
of
Gauge.		Diameter
of
Bore
by
Calcu-
lation.		Diameter
of
Balls
for
Proof.		Weight
of Balls
for
Proof.		Charges of Powder for Proof.
First Class.Second Class.
Definitive
Proof.		Provisional
Proof.		Definitive
Proof.
inches.inches.grains.grains.ozs.drs.grains.ozs.drs.grains.ozs.drs.
11·6691·6496752481211...481211...240658
21·3251·3053342232455 232455 11622101⁄2
31·1571·1072211153138 153138 766112
41·0521·03216491176211 1176211 588151⁄2
5·976·956131593022 93022 46511
6·819·8991090766112 766112 383...14
7·873·85393165618 65618 328...12
8·835·81581260216 60216 301...11
9·803·78372049212 49212 246...9
10·775·75564646511 46511 232...81⁄2
11·751·731586437...16 437...16 219...8
12·729·709535437...16 437...16 219...8
13·710·690493410...15 410...15 205...71⁄2
14·693·673457383...14 383...14 191...7
15·677·657425383...14 383...14 191...7
16·662·642399369...131⁄2369...131⁄2185...63⁄4
17·649·629374369...131⁄2369...131⁄2185...63⁄4
18·637·617352342...121⁄2342...121⁄2171...61⁄4
19·626·606334301...11 301...11 150...51⁄2
20·615·595316273...10 273...10 137...5
21·605·585300273...10 273...10 137...5
22·596·576287246...9 246...9 123...41⁄2
23·587·567274246...9 246...9 123...41⁄2
24·579·559262232...81⁄2232...81⁄2116...41⁄4
25·571·551251232...81⁄2232...81⁄2116...41⁄4
26·563·543242232...81⁄2232...81⁄2116...41⁄4
27·556·536231232...81⁄2232...81⁄2116...41⁄4
28·550·530223232...81⁄2232...81⁄2116...41⁄4
29·543·523214205...71⁄2205...71⁄2102...33⁄4
30·537·517207205...71⁄2205...71⁄2102...33⁄4
31·531·511—205...71⁄2205...71⁄2102...33⁄4
32·526·506194205...71⁄2205...71⁄2102...33⁄4
33·520·500—191...7 191...7 96...31⁄2
34·515·495182191...7 191...7 96...31⁄2
35·510·490—191...7 191...7 96...31⁄2
36·506·486172191...7 191...7 96...31⁄2
37·501·481—191...7 191...7 96...31⁄2
38·497·477162178...61⁄2178...61⁄289...31⁄4
39·492·472—178...61⁄2178...61⁄289...31⁄4
40·488·468154178...61⁄2178...61⁄289...31⁄4
41·484·464—164...6 164...6 82...3
42·480·460146164...6 164...6 82...3
43·476·456—164...6 164...6 82...3
44·473·453139164...6 164...6 82...3
45·469·449—150...51⁄2150...51⁄275...23⁄4
46·466·446133150...51⁄2150...51⁄275...23⁄4
47·463·443—150...51⁄2150...51⁄275...23⁄4
48·459·439127150...51⁄2150...51⁄275...23⁄4
49·456·436—150...51⁄2150...51⁄275...23⁄4
50·453·433122150...51⁄2150...51⁄275...23⁄4
Number
of
Gauge.		Diameter
of
Bore
by
Calcu-
lation.		Diameter
of
Balls
for
Proof.		Weight
of Balls
for
Proof.		Charges of Powder for Proof.
Third Class.Fourth Class.
Definitive
Proof.		Provisional
Proof.		Definitive
Proof.
inches.inches.grains.grains.ozs.drs.grains.ozs.drs.grains.ozs.drs.
11·6691·649675238508123⁄438508123⁄4240658
21·3251·3053342185944 185944 11622101⁄2
31·1571·107221112252123⁄412252123⁄4766112
41·0521·0321649941221⁄2941221⁄2588151⁄2
5·976·95613157441111⁄47441111⁄446511
6·819·8991090612161⁄2612161⁄2383...14
7·873·853931525131⁄4525131⁄4328...12
8·835·815812481111⁄2481111⁄2301...11
9·803·783720394...141⁄2394...141⁄2246...9
10·775·755646372...131⁄2372...131⁄2232...81⁄2
11·751·731586350...123⁄4350...123⁄4219...8
12·729·709535350...123⁄4350...123⁄4219...8
13·710·690493328...12 328...12 205...71⁄2
14·693·673457306...111⁄4306...111⁄4191...7
15·677·657425306...111⁄4306...111⁄4191...7
16·662·642399295...103⁄4295...103⁄4185...63⁄4
17·649·629374295...103⁄4295...103⁄4185...63⁄4
18·637·617352273...10 273...10 171...61⁄4
19·626·606334241...83⁄4241...83⁄4150...51⁄2
20·615·595316219...8 219...8 137...5
21·605·585300219...8 219...8 137...5
22·596·576287197...71⁄4197...71⁄4123...41⁄2
23·587·567274197...71⁄4197...71⁄4123...41⁄2
24·579·559262186...63⁄4186...63⁄4116...41⁄4
25·571·551251186...63⁄4186...63⁄4116...41⁄4
26·563·543242186...63⁄4186...63⁄4116...41⁄4
27·556·536231186...63⁄4186...63⁄4116...41⁄4
28·550·530223186...63⁄4186...63⁄4116...41⁄4
29·543·523214164...6 164...6 102...33⁄4
30·537·517207164...6 164...6 102...33⁄4
31·531·511—164...6 164...6 102...33⁄4
32·526·506194164...6 164...6 102...33⁄4
33·520·500—153...51⁄2153...51⁄296...31⁄2
34·515·495182153...51⁄2153...51⁄296...31⁄2
35·510·490—153...51⁄2153...51⁄296...31⁄2
36·506·486172153...51⁄2153...51⁄296...31⁄2
37·501·481—153...51⁄2153...51⁄296...31⁄2
38·497·477162142...51⁄4142...51⁄489...31⁄4
39·492·472—142...51⁄4142...51⁄489...31⁄4
40·488·468154142...51⁄4142...51⁄489...31⁄4
41·484·464—131...43⁄4131...43⁄482...3
42·480·460146131...43⁄4131...43⁄482...3
43·476·456—131...43⁄4131...43⁄482...3
44·473·453139131...43⁄4131...43⁄482...3
45·469·449—120...41⁄2120...41⁄275...23⁄4
46·466·446133120...41⁄2120...41⁄275...23⁄4
47·463·443—120...41⁄2120...41⁄275...23⁄4
48·459·439127120...41⁄2120...41⁄275...23⁄4
49·456·436—120...41⁄2120...41⁄275...23⁄4
50·453·433122120...41⁄2120...41⁄275...23⁄4

N.B.—Revolving Arms of the Fifth Class shall be proved once only, and such Proof shall be by the Scale laid down for definitive Proof of the Fourth Class.

As soon as a number of gun barrels are loaded according to the foregoing scale, they are taken to a house or detached building, standing apart from other offices. (The [woodcut] represents the interior accurately.) The house is lined throughout with thick sheet iron, and the windows, which resemble Venetian blinds, are constructed of the same metal. Iron frames are laid the whole length of the room; on these the barrels of various qualities, when about to be fired, are placed. In the front of these frames lies a large mass of sand, to receive the balls. Behind the frame, on which the twist barrels are fixed, lies another bed of sand; in which, on the recoil, the barrels are buried. Behind the frame, on which the common barrels or muskets are tried, a strong iron bar is placed, having a number of holes large enough to receive the tang of the breech, but not the barrel. The barrels being thus fixed, it is impossible for them to fly back. A groove runs along the whole length of each frame, in which the train of powder is strewed to ignite the charges, upon which the barrels are laid, with the touch-holes downwards.