DEEP-SEA LIGHTHOUSES.

Inangahua Times, Volume VIII, Issue 1275, 25 July 1883, Page 2

DEEP-SEA LIGHTHOUSES.

(Irom "Iron.") The paper read by Mr Chris. Anderson, of Leeds, before the Society of Engineers, on the construction of deep-sea lighthouses "will, we hope, attract the attention it deserves. MiAnderson proposes .to construct such lighthouses of hollow rivetted ironwork in the form of a large cylinder, about 36ft diameter, and 290 in length, consisting of three essential parts. The upper portion, rising 140 ft out of the water, is to be similar, so far as shape, arrangement, and internal fittings are concerned, to the tower of an ordinary light-house. The central portion, about water-line, is to be packed with a material (such as corkwood) much lighter than water and capable of forming a durable and unsinkable floating tower. The lower portion, extending to 150 ft bf dow the water-line, is intended to counteract the force of wind and weather acting upon the tower, and as ballest to lower the centre of gravity of the whole structure to any desired extent. To this compartment water is admitted,, and if necessary a quantity of iron ballast can be employed. The lighthouse is to be erected complete in the shipbuilding, yard, launched, and towed out to its intended site, where it will readily be made to assume its erect position by admitting water to the lower compartment. Having been properly floated and ballasted, it is securely attached by. steel wire ropes 2in in diameter to anchor blocks, weighing about 200 tons each, sunk in suitable positions, so that in water one mile deep each rope would be from two to three miles long. The proposed displacement is about 2000 tons, for which there would be no difficulty in providing adequate moorings. The structure is entirely dependent for its floating power upon the light material contained in the central division and consequently unsinkable, even if damaged by collision with a ship or an iceberg. Owing to its peculiar form and arrangement, its stability is very great so that if forced from its perpendicular, it would instantly right itself with great power. The author has calculated that a hurricane moving with a velocity of 100 miles per hour, equivalent to pressure of 501 b per square foot, will only cause a deviation of 10 degrees from the perpendicular. Against this it is to be noticed that the sag of the mooring ropes will form a most effective spring to control any tendency to oscillation. As the whole mass of the structure is comparatively light, and the area exposed to the lifting force of waves very small indeed, it is thought bhe rising and falling motion caused by passing waves will be almost inippreciable. The extreme desirability uid increasing necessity for lighthouses md telegraphic stations in mid-ocean ,s universally admitted. The following

important objects to. be attained by their construction may be briefly stated : — l , for meteorological purposes as from a station say 1000 miles from our shores, a storm warning from the Atlantic could be sent 36 hours in advance, and a yearly saving of many million pounds' worth . of maritime property and of hundreds of human lives thereby effected. 2. Shipowners could be apprised of the passage and condition of their vessels, andcould forward messages to the same en route. 3. To afford rendezvous for vessels in distress or shipwrecked crews. The author also- proposes to eriiplby similar lighthouses on a smaller scale for coast service. The immense saving of life and property which would result around the shores of the United Kingdom would be sufficient in one year alone to recoup their cost many times over. As we pride ourselves on being an eminently seafaring nation, it should follow that the above invention, which Certainly tends towards rendering navigation safer, and communication with ships in distress easier, would receive more than ordiuary support. The scheme is ingenious, and, we think, perfectly practicable.