Mercury Chlorate fulminate. of potash. Specification 91.31 8.69 _6.--Ballistic-Pendulum Tests._ This record includes powder used, weight of charge, swing of mortar, and unit disruptive charge, the latter being the charge required to produce a swing of the mortar equal to that produced by ½ lb. (227 grammes) of 40% dynamite, or 3.01 in. _7.--Record of Tests._ Tests Nos. 1 to 5 in Gallery No. 1, as set forth in preceding circular. _8.--Trauzl Lead-Block Test._ Powder and test numbers, expansion of bore-hole in cubic centimeters, and average expansion compared with that produced by a like quantity (10 grammes) of 40% dynamite, the latter giving an average expansion of 294 cu. cm. _9.--Pressure Gauge._ Powder and test number, weight of charge, charging density, height of curve, pressure developed, and pressure developed after cooling, compared with pressure developed after elimination of surface influences by a like quantity (100 grammes) of 40% dynamite, the average being 8,439 kg. per sq. cm. _10.--Rate of Detonation._ Powder and test number, size of cartridge, and rate of detonation in meters per second, for comparison with rate of detonation of 40% dynamite, which, under the same conditions, averages 4,690 m. per sec. _11.--Impact Machine._ Explosive and test numbers, distance of fall (2,000-gramme weight) necessary to cause explosion, for comparison with length of fall, 11 cm., necessary to cause explosion of 40% dynamite. _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._ Number of large calories developed per kilogramme of explosive, for comparison with 1,000 grammes of 40% dynamite, which develop, on an average, 1,229 large calories. Blasting Powder Separator.