Harbour works -- Bo Pheg beacon -- Light-keepers’ and seamen’s houses -- Concluding works on the Rock, such as pointing, &c. -- Interior fittings of the Tower -- Light-room apparatus, and first exhibition of the Light -- Removal of the barrack from the Rock -- Expense, 169 PART II. NOTES ON THE ILLUMINATION OF LIGHTHOUSES, WITH SHORT NOTICES OF THEIR HISTORY, 181. Early history, 181 -- Colossus of Rhodes, 182 -- Pharos of Alexandria, 183 -- Coruna Tower, 187 -- Lighthouse at the mouth of the Quadalquivir, 188 -- Ancient Phari in Britain, 188 -- Tour de Corduan, 189 -- Eddystone, 189 -- Bell Rock, 192 -- Carlingford, 194 -- Iron lighthouses, 194 -- Early modes of illumination, 195 -- Flame, 196 -- Drummond and Voltaic Lights, 199 -- Mr Gurney’s Lamp, 200 -- Argand Burners, 200. CATOPTRIC SYSTEM OF LIGHTS, 204. Application of Paraboloidal Mirrors, 205 -- Reflection, 207 -- Paraboloidal Mirrors, 209 -- Divergence of Paraboloidal Mirrors, 212 -- Effect of Paraboloidal Mirrors, 217 -- Power of ditto, 218 -- Manufacture of reflectors, 218 -- Testing of mirrors, 219 -- Argand Lamps used in reflectors, 220 -- Arrangements for raising or lowering the Argand wick, 222 -- Flowing of the lamp, 223 -- Placing the lamp in the focus, 226 -- Distinctions of Catoptric Lights, 227 -- Colour as a distinction for lights, 229 -- Arrangement of reflectors on the frame, 230 -- Bordier Marcet’s reflectors, 232 -- Fanal sidéral, 232 -- Fanal à double effet, 234 -- Fanal à double face, 236 -- Mr Barlow’s spherical mirrors, 237 -- Captain Smith’s mirrors in the form of a parabolic spindle, 238. DIOPTRIC SYSTEM OF LIGHTS, 239.