The following table shows the composition of the more important kinds.

Name of Powder.

Sulphur.

Saltpetre.

Sodium Nitrate.

Potassium Chlorate.

Nitroglycerine.

Guncottcn.

Charcoal.

Sawdust.

Other Ingredients and Notes.

Bennett .

X

X

x

Ordinary powder with 7 per cent of gypsum.

Lannoy ,. .

X

X

X

Davey..

X

X

+ starch.

Pyronome..

20

52.5

+ 27.5 tan.

Oxland • • •.

16

85

18

+ 20 lignite.

Robert Dole

X

X

X

+ 18 dehydrated sodium sulphate.

Schwartz (I.) .

9.2

48.6

26.5

14.7

,, (11.)

9.6

56

18.1

15

Kup..

9

66

8

16

Budenberg.

10

34

40

8

+ 4 lignite + 4 sodium tartrate.

Kellow and Short

10

10

20

10

+ 64 tan.

Spence..

X

X

+ sodium carbonate or starch.

Vynaud . .

2

22

+ 76 barium nitrate.

Neumeyer.. - .

X

X

+ potassium cyanide.

White powder .

-

1

+ 1 potassium cyanide + 1 sugar.

Dynamite . .

78

+ 22 sand.

Dualine . .

80

20

Rendrock .

40

40

+ 13 cellulose + 7 paraffia.

Giant powder .

8

40

36

8

Vulcan .

7

48

35

10

Mica..

52

+ 48 mica.

Hercules .

1

77

+ 2 cellulose + 20 magnesium carbonate.

Electric .

33

Rest unkuown.

Dessignolles

50

+ 50 potassium picrate + charcoal if used for cannons or small firearms.

Brugeres . .

50

+ 50 ammonium picrate.

Tonite .

62.5

+ 47.5 barium nitrate.

Explosive gelatine

89

7

+ 4 camphor.

Atlas A...

2

75

21

+ 2 magnesium carbonot

,, B . . .

34

50

14

+ 2 magnesium carbonat .

Judson (No 2) .

13.5

60

20

12.6

„ (No. 3) .

16

64

5

15

Rackarock.

77.5

22.5

-

Forcite ,.

95

5

Gelignite .

32

56.5

3.3

8

Pyrolite(l)

20

51

1.5

11

. (II.) .

17

13

1.7

12

+ 6 sodium sulphate.

Saxifragine (1)••

21

+ 77 barium nitrate.

(II.)

2

22

+ 76

American powder

49

+ 23 sugar + 28 potassium cyanide.

Erhardt . .

1

1

4

+ 2 tannin material.

Hahn..

367.5

18

+ 46 spermaceti + 168*5 antimony sulphide.

Horsley . ..

9

+ 3 powdered galls.

Spence .

20

2

7

+ 2 oil + 5 sodium carbonate.

Roburite . .

X

+ nitronaphthalenc.

GarbodynamV.3.

90

10

Meganite . .

X

X

X

Fortis..

X

X

+ tan.

Cordite or Abel.

92

8

Green powder .

70

+ 20 picric acid + 10 potassium cyanide.

Note. X denotes that the amount of ingredient present is unknown. (Industries)

The piston weighs 12 1/4 lb., and the explosive is placed in a parabola-shaped cavity at its top. The shot was also made of tempered steel, 4 in. diameter and 10 in. long, and weighed 34 1/2 lb.

The instrument is worked in the following manner: - The lead plug is placed upon the steel plate, the piston is placed gently upon it, and the shot next lowered upon it. The fuse is lighted, and the charge, in exploding, throws out the shot and compresses the lead plug. The accuracy of the test is based upon the assumption that the lead plugs are of uniform density and homogeneous in structure, and the author, by cutting his plugs from bars of pure lead manufactured from large masses of metal at a high temperature, believes that the error from want of these conditions is reduced to a minimum. The amount of compression is finally expressed in ft. lb. by plotting the actual compressions measured by the Quinan gauge against the work actually done on the lead by known pressures. The author, however, did not plot out his results in this manner, but preferred simply to use the method for determining the relative strengths of the explosives examined, instead of calculating from the observed pompres-sions the absolute pressures exerted.

The following table gives a summary of the results obtained, the order of strength being given in numbers, nitroglycerine having assigned to it the value of 100: -

Name of Explodre.

Compression of Cylinder, In.

Order of Strength.

Explosive gelatine (made by Vouge's process)

0.585 .

106.17

Hellhoffite

0.585 .

106.17

Nitro-glycerine (old)

0.551 .

100.00

Nobel's smokeless powder .....

0.509 .

92.38

Nitro-glycerine

(fresh) .........

0.509 .

92.37

Explosive glycerine (made from above)

0.490 .

88.93

Gun-cotton (1889).

0.458 .

83.12

„ (1885).

0.458 .

83.12

Nitro-glycerine(made by French process)

0.451

81.85

Name of Explodre.Gun-cotton

Compression of Cylinder. In.

Order of Strength.

(laboratory)

0.448 .

81.31

Dynamite, No. 1 .

0.448 .

81.31

Dynamite deTranzl

0'437 .

79.31

Emmensite . .

0.429 .

77.86

Amide powder

0.385 .

69.87

Oxonite (from fused picric acid)

0.383 .

69.51

Tonite ...

0.376 .

68.24

Bellite...

0.362 .

65.70

Oxonite (picric acid not fused) .

0.354 .

64.24

Rack-a-rock .

0 340 .

61.71

Atlas powder.

0.333 .

60.43

Ammonia dynamite

0.332 .

60.25

Volney's powder, No. 1...

0322 .

58.44

Volney's powder No. 2...

0.294 .

53.18

Melinite..

0.280 .

50.82

Silver fulminate .

0.277 .

50.27

Mercury fulminate.

0.275 .

49.91

Mortar powder (Dupont)..

0.155 .

23.13

(Industries.)