CHAPTER IX.—­THE DETERMINATION OF THE RELATIVE STRENGTH OF EXPLOSIVES.

Effectiveness of an Explosive—­High and Low Explosives—­Theoretical Efficiency—­M.M.  Roux and Sarrau’s Results—­Abel and Noble’s—­Nobel’s Ballistic Test—­The Mortar—­Pressure or Crusher Gauge—­Calculation Volume of Gas Evolved, &c.—­Lead Cylinders—­The Foot-Pounds Machine—­Noble’s Pressure Gauge—­Lieut.  Walke’s Results—­Calculation of Pressure Developed by Dynamite and Gun-Cotton—­McNab’s and Ristori’s Results of Heat Developed by the Explosion of Various Explosives—­Composition of some of the Explosives in Common Use for Blasting, &c.

INDEX

LIST OF ILLUSTRATIONS.

Frontispiece—­Danger Building showing Protecting Mounds. 1.  Section of Nitro-Glycerine Conduit 2.  Melsens System of Lightning Conductors 3.  French System 4_a_ & 4_b_.  English Government System 5.  Upper Portion of Nitrator for Nitro-Glycerine 6.  Small Nitrator 7.  Nathan’s Nitrator 8.  Nitro-Glycerine Separator 9.  Nitro-Glycerine Filtering Apparatus
10.  Cotton-Waste Drier
11.  Dipping Tank
12.  Cooling Pits
13.  Steeping Pot for Gun-Cotton
14.  Hydro-Extractor or Centrifugal Drier
15_a_ & 15_b_.  Gun-Cotton Beater
16_a_.  Poacher for Pulping Gun-Cotton
16_b_.  Plan of same
16_c_.  Another form of Poacher
17 & 18.  Compressed Gun-Cotton
19.  Hydraulic Press
20.  Thomson’s Apparatus—­Elevation
21.  Elevation Plan
22.  Trench’s Safety Cartridge
23.  Vessel used in Nitrating Paper
24.  Cage ditto—­White & Schupphaus’ Apparatus
25.  Do. do. do.
26 & 27.  Nitrating Pot for Celluloid
28 & 29.  Plunge Tank in Plan and Section
30.  Messrs Werner, Pfleiderer & Perkins’ Mixing Machine
31.  M.  ‘Roberts’ Mixing Machine for Blasting Gelatine
32.  Plan of same
33.  Cartridge Machine for Gelatines
34.  Cartridge fitted with Fuse and Detonator
35.  Gun-Cotton Primer
36.  Electric Firing Apparatus
37.  Metal Drum for Winding Cordite
38.  Ten-Stranding
39.  Curve showing relation between Pressures of Cordite and Black Powder,
      by Professor Vivian Lewes
40.  Marshall’s Apparatus for Moisture in Cordite
41.  Lunge’s Nitrometer
42.  Modified do.
43.  Horn’s Nitrometer
44.  Schultze-Tieman Apparatus for Determination of Nitrogen in Gun-Cotton
45.  Decomposition Flask for Schultze-Tieman Method
46.  Abel’s Heat Test Apparatus
47.  Apparatus for Separation of Nitro-Glycerine from Dynamite
48.  Test Tube arranged for Heat Test
49.  Page’s Regulator
50.  Do. showing Bye-Pass and Cut-off Arrangement
51.  Will’s Apparatus
52 & 53.  Curves obtained
54.  Dynamite Mortar
55.  Quinan’s Pressure Gauge
56.  Steel Punch and Lead Cylinder for Use with Pressure Gauge
57.  Micrometer Calipers for Measuring Thickness of Lead Cylinders
58.  Section of Lead Cylinders before and after Explosion
59.  Noble’s Pressure Gauge
60.  Crusher Gauge