_12.--Distance of Explosive Wave Transmitted by 1.25 by 8-in.
Cartridge._

Explosive and test numbers, weight of cartridge, distance separating
cartridges in tests, resulting explosion or non-explosion, for
comparison with two cartridges of 40% dynamite, hung, under identical
conditions, 13 in. apart, end to end, in which case detonation of the
first cartridge will explode the second.

_13.--Flame Test._

Explosive and test numbers, charge 100 grammes with 1 lb. of clay
stemming, average length of flame and average duration of flame, for
comparison with photographs produced by 40% dynamite under like
conditions.

[Illustration: PLATE X.

Fig. 1.--Separator for Grading Black Powder.

Fig. 2.--Safety Lamp Testing Gallery.

Fig. 3.--Mine Gallery No. 2.]

_14.--Small Lead Blocks._

Powder and test numbers, weight of charge, and compression produced in
blocks.

_15.--Calories Developed._