1889. J Sir James N. Dour/las on Beacon Lights, &c. 425 



WEEKLY EVENING MEETING, 



Friday, March 15, 1889. 



Sir Frederick Bramwell, Bart. D.C.L. F.R.S. Honorary Secretary 

 and Vice-President, in the Chair. 



Sir James N. Douglass, F.E.S. M.B.L 



Beacon LigJits and Fog Signals. 



It is stated by Samuel Smiles, in his ' Lives of Engineers,' that 

 " with VVinstanley's structure on the Eddystone in 1696, may be said 

 to have commenced the modern engineering efforts," in directing the 

 great sources of power in nature, tor the use and convenience of man ; 

 efforts, which, followed up by Eudyerd, Smeaton, and others, have 

 been so successful in converting hidden dangers into sources of 

 safety, and ensuring the beneficent guidance of the mariner in his 

 trackless path. 



The famous structure of Smeaton, which had withstood tbe storms 

 of more than half a century with incalculable advantage to mankind, 

 became in course of time a matter of anxiety and w^atchful care to the 

 Corporation of Trinity House, owing to the great tremor of the 

 building with each wave stroke, during heavy westerly storms. The 

 joints of the masonry frequently yielded to the heavy strains, and 

 the sea-water was driven through them to the interior of the building. 

 The upper part of the structure was strengthened with internal iron- 

 work in 1839, and again in 1865. On the last occasion, it was found 

 that the chief mischief was caused by the upward stroke of the heavy 

 seas against the projecting cornice of the lantern gallery, thus lifting 

 this portion of the masonry, together with the lantern above it. 

 Unfortunately, the portion of the gneis rock on which the lighthouse 

 was founded, had become seriously shaken by the heavy sea strokes 

 on the tower, and the rock had thus been seriously undermined at its 

 base. The waves rose during storms considerably above the summit 

 of the lantern, thus frequently eclipsing the light, and altering its 

 distinctive character from a fixed light to an occulting. This matter 

 of distinctive character in a beacon light, was one of little importance 

 at the date of the erection of Smeaton's lighthouse, when coal fires 

 were the only illuminating agents along the coasts ; but with the 

 rapid development of our commerce, and the great increase in the 

 number of coast lights, it has become an absolute necessity that each 

 light maintain a clearly distinctive character. It was, therefore, 



