INDEX 



361 



Fire, 146 



Fire drill, 147 



Fire engine, 181 



Fireplace, 151, 152 



Fixer, acid, 318, 319 



Fixing bath, 317, 318, 323 



Fletcher of Rye, 119 



Flint, 49; and steel, 144 



Floating, explanation of, 116 



Flood, the, 40, 42 



Florida, coast of, 71 



Fluid pressure, 113, 114; law of, 114 



Fluorine, 166, 167, 169, 170, 172 



Fluorite, 50 



Flute, 333 



"Flying Cloud," 118 



Flying machines, early, 85 



Flywheel, 183 



Focal length of lens, 295, 311 



Foci, conjugate, 295 



Focus: of lens, 295, 310; of mirror, 291 



Formalhaut, 40 



Fossils, 71, 72 



Fracture, 49 



Franklin, Benjamin, 151, 204 



Friction, 341, 344 



Fulcrum, 340 



Fulton, Robert, 189 



Furnace, hot-air, 154, 155 



Furnace, puddling, 162 



Fuse box, 247 



Gabbro, 66, 69 



Galena, 48, 49, 50, 61 



Galvani, 205 



Galvanoscope, 208 



Gamma rays, 173 



Garnet, 51 



Gas: elasticity of, 138; natural, 76; 



nature of, in 

 Gasoline engine, 191, 192; parts of, 



192, 193; working of, 192 

 Gear shift, 197 

 Gear wheels, 345 

 Gemini, 34, 35 

 Geode, 54 

 Giants' Causeway, 69 



Gioja, Flavio, 200 



Glacial bowlders, 70 



Glider, 87-90 



Gneiss, 74 



Gnome engine, 95 



Goat, the, 39 



Gold, 45, 47 



Governor, 183, 185 



Graflex camera, 315, 316 



Granite, 45, 50, 66, 67, 74; pegmatite, 

 66, 67; porphyritic, 66, 67 



Gravity battery, 224 



Gray, Elisha, 218 



" Great Eastern," 69 



Greenstone, 69 



Grid, 269, 270 



Ground glass, 310 



Ground wire, 213, 256, 264 



Guericke, Otto, 203 



Gun: breech-loading, 140, 142; flint- 

 lock, 140, 141; locating by sound, 337 



Gun barrel, grooving, 142 



Gunpowder, 138, 139, 191; making, 139 



Gypsum, 2, 51, 56, 60 



Gyroscope, 133 



Halcyone, 31 



Halite, 50 



Halogens, 172 



Hammer, 342 



Hardness, 50; scale of, 50 



Hargrave, Lawrence, 79 



Harp, 328 



Harvester, 187 



Head set, 258 



Heat: conductivity of, 153; expansion 



by, 116; latent, 164; sensible, 164 

 Heater, electric, 247, 249 

 Heating plant: hot water, 154; steam, 



iS4 



Helen of Troy, 35 

 Helicopter, 90 

 Helium, 166, 167 

 Hematite, 48, 49, 50 

 Henry, Joseph, 218 

 Herschel, Sir William, 2 

 Heterodyne, 272 

 High-school attendance, increase of, 188 



