ON THE PREPARATION OF VACUUM TUBES FOR THE PRODUCTION OF PROFESSOR ROENTGEN'S RADIATION *

GLASS-GRINDING AND OPTICIANS' WORK *

§ 61. Details of the Process of Fine Grinding. — *

§ 62. Polishing. — *

§ 63. Centering. — *

§ 65. Preparing Small Mirrors for Galvanometers. — *

§ 66. Preparation of Large Mirrors or Lenses for Telescopes. — *

§ 69. The Preparation of Flat Surfaces of Rock Salt. — *

§ 70. Casting Specula for Mirrors. — *

§ 71. Grinding and polishing Specula. — *

§ 72. Preparation of Flat Surfaces. — *

§ 73. Polishing Flat Surfaces on Glass or on Speculum Metal. — *

MISCELLANEOUS PROCESSES *

§ 74. Coating Glass with Aluminium and Soldering Aluminium. — *

§ 75. The Use of the Diamond-cutting Wheel. — *

§ 76. Arming a Wheel. — *

§ 77. Cutting a Section. — *

§ 78. Grinding Rock Sections, or Thin Slips of any Hard Material.— *

§ 79. Cutting Sections of Soft Substances. — *

§ 80. On the Production of Quartz Threads.' — *

§ 84. Drawing Quartz Threads. — *

§ 86. Drawing Threads by the Catapult. — *

§ 87. Drawing Threads by the Flame alone. — *

§ 88. Properties of Threads. — *

§ 90. On the Attachment of Quartz Fibres. — *

§ 91. Other Modes of soldering Quartz. — *

§ 92. Soldering. — *

§ 94. Preparing a Soldering Bit. — *

§ 95. Soft Soldering. — *

§ 97. Soldering Zinc. — *

§ 98. Soldering other Metals — *

§ 99. Brazing. *

§ 100. Silver Soldering. —