Contents.
| PART I. | |
| ACCOUNT OF SKERRYVORE LIGHTHOUSE. | |
| Page | |
| Introduction — Constitution of the Lighthouse Board — Lights established since 1821 — Improvements in the mode of illumination — Dioptric Lights — Beacons and Buoys, | 9 |
| CHAPTER I. | |
| Topographic notice of the Skerryvore Rock, | 19 |
| CHAPTER II. | |
| Preliminary arrangements and works, including survey of the rocks, and opening of quarries from 1834 to 1837 — Survey of the Skerryvore rocks — Disadvantages of Tyree — Pier and workyard at Hynish, Tyree — Quarries at Hynish — Skerryvore Committee appointed, | 37 |
| CHAPTER III. | |
| On the construction of Lighthouse Towers, | 45 |
| CHAPTER IV. OPERATIONS OF 1838. | |
| Temporary Barrack on Rock — Tools and machinery — Steam Tender for the works — Employment and wages of workmen — Progress of the outfit for the season’s operations — Embark for Skerryvore — Lay down moorings, and try to land on the Rock — Driven to Mull — First day’s work on the Rock — Shipment of materials at Glasgow and Greenock — Reach Tyree — Driven to Mull — Return to Tyree — First good day’s work on the Rock — Sudden gale and great peril to the vessels — Reach Hynish in safety — Detained by bad weather four days at Hynish — Return to the Rock and have six days of good weather — Erection of the pyramid of the wooden barrack — Mode of determining the length of the beams, and the sites for their fixtures — Pyramid completed — Mode of living while erecting the barrack — Shoals of Medusæ seen — Driven by a gale to Mull — Return to Hynish and are driven to Coll — Return to the Rock — Driven to Tyree — Return to the Rock — Horizontal braces fixed — Driven to Mull — Heavy gale — Timber cast on Tyree — Return to Rock and further progress of barrack — Last day’s work on Rock this season — Precaution for the benefit of shipwrecked seamen — View from top of pyramid — Destruction of the barrack during a gale — Letter from Mr Hogben — Proceed to Skerryvore — State in which the Rock was found — Cause of the destruction of the barrack — Preparations for a new barrack — Works at Hynish — Hynish quarries, | 71 |
| CHAPTER V. OPERATIONS OF 1839. | |
| Shipping station and pier at Hynish — Granite quarries in Mull — Observations on the quarrying of granite — Dressing of the Lighthouse blocks — Excavation of foundation for the Lighthouse Tower on the Skerryvore Rock — Fitting up of the second barrack on the Rock — Sudden death of George Middlemiss — Wharf and landing-place on the Rock — Ring-bolts, water-tanks, and railways — Incidents of the season — Effects of a gale from the south-west — Mutiny of the crew — Near approach of the vessels to the Rock, and other circumstances shewing the importance of a Light on the Skerryvore, | 107 |
| CHAPTER VI. OPERATIONS OF 1840. | |
| Hynish workyard — Hynish pier — The Rock — Life in the barrack — Foundation-pit — Landing of the materials on the Rock — Laying the first stone, | 140 |
| CHAPTER VII. OPERATIONS OF 1841. | |
| Hynish workyard — The Rock — The waves — Colours of the breaking waves — The seals, | 151 |
| CHAPTER VIII. OPERATIONS OF 1842. | |
| State of the Rock in Spring of 1842 — Commencement of Rock operations — Last stone — The Lantern, | 163 |
| CHAPTER IX. CONCLUDING OPERATIONS AND EXHIBITION OF THE LIGHT. | |
| 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. | |
| Early history of Lighthouse lenses, Condorcet, Buffon, Brewster, Fresnel, 239 — Refraction, 242 — Lenses, 245 — Spherical aberration, 248 — Fresnel’s formulæ for annular lenses, 249 — Testing lenses, 255 — Divergence of lenses, 256 — Illuminating power of lenses, 257 — Arrangement of lenses in a Lighthouse, 258 — Pyramidal lenses and mirrors, 259 — Curved mirrors, 260 — Cylindric refractors of fixed Lights, 263 — Application of crossed prisms to cause flashes, 264 — True cylindric form given to refractors, and other improvements in their construction, 264 — Catadioptric zones, the mode of computing their elements, &c., 267 — Testing of zones, 282 — Framing of zones, 286 — Mechanical lamp, 286 — Height of flame of mechanical lamp, 289 — Position of flame in reference to focus, 290 — Working of the pumps, 291 — Choice of focal point for various parts of apparatus, 292 — Choice of a focal point for zones, 292 — Application of spherical mirrors to fixed Dioptric Lights, 293 — Arrangement of Dioptric apparatus, 293 — Arrangement of Dioptric apparatus in Lightroom, 294 — Power of Dioptric instruments, 298 — Orders of French Lights, 298 — Distinctions of Dioptric Lights, 299 — Comparison of Dioptric and Catoptric apparatus for revolving lights, 301 — Comparison for fixed lights, 303 — Summary of views as to two systems for revolving lights, 306 — Summary of views as to two systems for fixed lights, 306 — Advantages and disadvantages of both systems under certain circumstances, 308 — Distinctions of the Dioptric Lights and the application of coloured media, 311 — Captain Basil Hall’s proposal for fixed lights, 313 — Effects of rapid motion on the power of lights, 315 — Connection of experiments with irradiation, 320. | |
| VARIOUS GENERAL CONSIDERATIONS CONNECTED WITH LIGHTHOUSES, 320. | |
| Masking Lights, 320 — Double Lights, 322 — Leading Lights, 323 — Distribution of Lights on a coast, 325 — Height of Lighthouse Tower, and its relation to range of light, 328 — Diagonal Lantern, 330 — Glazing of Lantern, 331 — Ventilation of Lanterns, 331 — Arrangements and Management of a Lighthouse, 334 — Cleansing of apparatus, 335 — Mode of measuring relative power of lights, 336 — More accurate comparison of intensity of lights, 338 — Floating Lights, 346 — Beacons and Buoys, 347. | |