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. Lungé'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
NITRO-EXPLOSIVES.
CHAPTER I.
INTRODUCTORY.
The Nitro-Explosives—Substances that have been Nitrated—The Danger Area—
Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.
The manufacture of the various nitro-explosives has made great advances during late years, and the various forms of nitro-compounds are gradually replacing the older forms of explosives, both for blasting purposes and also for propulsive agents, under the form of smokeless powders. The nitro-explosives belong to the so-called High Explosives, and may be defined as any chemical compound possessed of explosive properties, or capable of combining with metals to form an explosive compound, which is produced by the chemical action of nitric acid, either alone or mixed with sulphuric acid, upon any carbonaceous substance, whether such compound is mechanically mixed with other substances or not.[A]
[Footnote A: Definition given in Order of Council, No. 1, Explosives Act, 1875.]
The number of compounds and mixtures included under this definition is very large, and they are of very different chemical composition. Among the substances that have been nitrated are:—Cellulose, under various forms, e.g., cotton, lignin, &c.; glycerine, benzene, starch, jute, sugar, phenol, wood, straw, and even such substances as treacle and horse-dung. Some of these are not made upon the large scale, others are but little used. Those of most importance are nitro-glycerine and nitro-cellulose. The former enters into the composition of all dynamites, and several smokeless powders; and the second includes gun-cotton, collodion-cotton, nitrated wood, and the majority of the smokeless powders, which consist generally of nitro-cotton, nitro-lignin, nitro-jute, &c. &c., together with metallic nitrates, or nitro-glycerine.
The nitro-explosives consist generally of some organic substance in which the NO_{2} group, known as nitryl, has been substituted in place of hydrogen.
Thus in glycerine,