472 



INDEX TO VOLUME 7. 



GRAY, J. MACFARLANE. 



Gray, J. McFarlane, steam-steering 

 engine for Great Eastern, dis- 

 cussion of paper by, 124, 125. 



Gyrometer, liquid, 112 ; action of, 

 113; applications of, 115; auto- 

 matic dip of cup in, 114 ; correc- 

 tion for lower orifice of cup of, 

 117 ; description of, 113 ; power 

 absorbed in, 114; range of power 

 in, 115 ; rotation of liquid in outer 

 vessel, how prevented, 113 ; uni- 

 form rotation produced by, 114 ; 

 velocity of, excess of calculated 

 over actual, 118 ; velocity of, 

 formula to compute, 118 ; vertical 

 position indifferent to, 120. 



Gyrometric governor. See Governor, 

 gyrometric. 



HALL, condenser of, 12. 



Head, Jeremiah, steam-engine go- 

 vernor, with nearly perfect action, 

 discussion of paper by, 139-141. 



Head, John, combustion of refuse 

 vegetable substances under steam- 

 boilers, discussion of paper by, 

 168-170. 



Heat, Carnot on, 32 ; Clapeyron on, 

 32 ; consumption of, in expansion, 

 28; conversion of , into mechanical 

 effect, 29 ; curve of equal, 33 ; 

 (dynamical tlieary of, 30, 62 ; 

 Helmholtz, Mayer, Eankine,Thom- 

 son on, reference to, 32 ; practical 

 application of, 52 ; Kegnault's ex- 

 perimental proof of, 54) ; econo- 

 mical application of, 62 ; (engine, 

 formula to express power of, 37 ; 

 Holtzmanon, 32; relative economy 

 of, 38) ; identity of, and dynamical 

 effect, 53 ; lost, 62 ; (material 

 theory of, 29, 30 ; disproved by 

 Davy, Dulong, Joule, 30 ; how 

 explained, 30) ; scientific applica- 

 tion of, 62 ; specific, proportionate 

 to expansion, 34 ; theoretical views 



JOY, D. 



regarding, 29 ; undulatory theory 

 of, 29 ; (unit of, 31, 53 ; Joule's, 31, 

 74 ; results by different observers, 

 32 ; unaffected by material, 31). 



Heating by steam. See Steam, Heat- 

 ing by. 



Heating furnaces, application of 

 regenerators to, 93. 



Helmholtz on heat, reference to, 32. 



High pressure engines, reference to, 4. 

 See Eegenerative Condenser for. 



Holtzman on heat, reference to, 32. 



Hornblower. surface condenser of, 12. 



Hot-blast stoves. See Kegenerative 

 hot-blast stoves. 



ILLUMINATING gas, 181 ; first em- 

 ployed in 1792, 181 ; illuminating 

 power of increased by drawing 

 from bottom of retort, 100, 101 ; 

 value of bye-products from, 186. 



Injection condenser. See Eegenera- 

 tive condenser. 



Injector. See Giffard injector. 



Interchanger of temperature, Sie- 

 mens's, 0. W., for refrigerating 

 machinery, 193, 194, 201. 



Iron, temperature of maximum 

 strength of, 58. 



Irvine, latent heat, experiments on, 

 18. 



Isolated steam. See Steam. 



JAMESON, J. W., combined vapour- 

 engine and expansive engine, dis- 

 cussion of paper by, 69-72. 



Jet. See Steam jet. 



Jones's coal-getting machine, 129. 



Joule, material theory of heat dis- 

 proved by, 30. 



Joule's unit of heat, 31, 74 ; views 

 regarding elastic pressure, 31. 



Joy, D., reversing and expansive 

 valve-gear, discussion of paper by, 

 173, 174. 



