---- ----, Fisher's, 37 ---- mechanical mine, 21 F. Failure of offensive torpedoes, the, 8 Fastest vessel in the world, the, 177 Final Russian torpedo boat attack, the, 203 Firing batteries, 75 ---- by cross bearings, 70 ---- ---- intersectional arcs, 71 ---- ---- observation, 69 ---- ---- preconcerted signal, 71 ---- Harvey's torpedoes, mode of, 121 ---- keys, 80 ---- ----, description of a series of, 81 ---- ----, Morse, 81 ----, mode of, 205 ---- ----, in 1829, 6 ---- Whitehead torpedoes, Thornycroft's method of, 140 Fish torpedo, adjustments of Whitehead's, 136 ---- ----, description of the, 133 ---- ----, invention and adoption of the, 131 ---- ----, methods of projecting the, 138 ---- ----, the mode of ignition of the, 135 Fish torpedoes in war, employment of, 133 ---- ----, Thornycroft's method of firing, 140 ---- ----, Woolwich, 140 Fisher's extempore high tension fuze, 37 Floating torpedoes, 116 Flotation experiment with a torpedo boat, 171 Fluid batteries, double, 274 ---- ----, single and double, 272 Fluid cell, action in a single, 273 Force compared, explosive effect and, 204 ----, definition of the term explosive, 204 ----, electro-motive, 270 ----, Voltaic battery test for electro-motive, 105 Forces, comparing electro-motive, 94 Fore and aft mooring, 56 Form of Lay's torpedo boat, an improved, 153 ---- ---- torpedo case, 31 Fosberry's patent torpedo boat protective, 182 Frame torpedoes, 18 Frames, projecting, 111 Franco-German war, torpedo operations during the, 192 ---- ----, torpedoes in the, 13 French submarine boat _Plongeur_, 185 ---- torpedo launches, Thornycroft's, 165, 169 ---- towing torpedoes, 131 Frictional electric machine, description of a, 278 ---- electricity, 278 Fulminate of mercury, 215 Fulton, Robert, 2 Fulton's attempt against the _Argus_, 6 ---- block ship, 5 ---- cable cutters, 5 ---- destruction of the _Dorothea_, 4 ---- drifting torpedoes, 5 ---- failures, 2 ---- French torpedo experiments, 3 ---- harpoon torpedoes, 5 ---- practical experiments, 5 ---- return to America, 4 ---- spar torpedoes, 5 ---- stationary submarine mines, 5 Fuzes, Abel's, 37 ----, Beardslee's, 35 ----, chemical, 23 ----, defects of chemical, 24 ----, electric, 33 ----, extempore, 37 ----, extempore, Fisher's, 37 ---- for conductivity, test of platinum wire, 101 ----, high tension, 34 ----, improved form of Jacobi's, 24 ----, McEvoy's percussion, 24 ----, percussion, 23 ----, platinum wire, 33 ----, ----, English service, 33 ----, ----, McEvoy's, 34 ----, sensitive, 23 ----, Statham's, 35 ----, test of resistance of platinum wire, 101 ----, testing high tension, 102 ----, Von Ebner's, 36