_Hadfield_, effect of temperature on hardness of steel, 4. _Harris_, indicator, 121. _Holborn-Kurlbaum_, optical pyrometer, 181. _Holden-d’Arsonval_, galvanometer, 45. _Holman_, formula for thermal junctions, 62. _Howe_, colour-temperature table, 167. Indicators, for radiation pyrometers, 156. — for resistance pyrometers, 118-124. — special range, 71. — standardizing of, 54, 108, 157. — for thermo-electric pyrometers, 45-53. Installations of resistance pyrometers, 130. — of thermo-electric pyrometers, 89. _Joly_, meldometer, 220. _Kelvin_, thermodynamic scale of temperature, 9. _Kowalke_, base-metal couples, 30. _Lambert_, anti-vibration stand for galvanometers, 47. _Le Chatelier_, optical pyrometer, 177. — thermo-electric pyrometer, 5, 22. _Leeds-Northrup_, indicator, 122. — recorders, 85, 127. — resistance pyrometers, 115. Liquid element thermocouples, 43. _Lovibond_, optical pyrometer, 186. Low temperatures, measurement of, 97, 132. Meldometer, 220. Mercury thermometer, limits of, 1. _Mesuré and Nouel_, optical pyrometer, 187. _Morse_, optical pyrometer, 182. National Physical Laboratory, scale of temperatures, 17. _Newton_, researches on high temperatures, 2. _Northrup_, molten tin pyrometer, 216. — pyrovolter, 74. Optical pyrometers, 167. — — management of, 192. — — special uses of, 193. _Paul_, base-metal pyrometer, 39. — compensator, 70. — radiation pyrometer, 155. — recorder, 83. — uni-pivot indicator, 49. _Peake_, compensated leads, 67. Pivoted galvanometers, 49. _Planck_, modifications of Wien’s formula, 171. Platinum scale of temperatures, 106. Pneumatic pyrometers, 217. Potentiometer indicators, 73. — method for measurement of E.M.F., 63. _Prinsep_, gas pyrometer, 3. Protecting sheaths for pyrometers, 34. Pyrometer, definition of, 1. Pyromike, 189. Radiation pyrometers, 134. — — calibration of, 157. — — indicators for, 156. — — management of, 161. — — recorders for, 161. — — special uses of, 164. _Rasch_, luminosity formula, 168. Recalescence of steel, 4, 94. Recorders for radiation pyrometers, 161. — — resistance pyrometers, 124. — — thermo-electric pyrometers, 75. Resistance, measurement of, 102. — of platinum, 105. Resistance pyrometers, 101. — — indicators for, 118. — — management of, 130. — — recorders for, 124. — — special uses of, 132. — pyrometry, terms used in, 111. _Roberts-Austen_, recorder, 76.