COLOURED LIGHTS. 187 



the appearance which is desired. Trial has been made of various colours, but red, blue, 

 and ^reen alone have been found useful, and the two latter only at distances so short as 

 to render them altogether unfit for sea-lights. Owing to the depth of tint which is 

 required to produce a marked effect, the red shades generally used absorb from four- 

 sevenths to five-sixths of the whole light an enormous loss, and sufficient to discourage 

 the adoption of that mode of distinction in every situation where it can possibly bo 

 avoided. The red glass used in France absorbs only four-sevenths of the light, but its 

 colour produces, as might be expected, a much less marked distinction to the seaman's 

 eye. In the lighthouses of Scotland a simple and convenient arrangement exists for 

 colouring the lights, which consists in using chimneys of red glass, instead of placing 

 large discs in front of the reflectors." 



The construction of the lantern is a point of importance; and one of the first order 

 will cost about 1,260. On the level of the top of the lower glass a narrow gangway 

 is usually built for the keeper to stand upon in order to clean the panes, an operation 

 which in snowy weather may have to be frequently repeated during the night. At some 

 of the lighthouses on the Mediterranean the lantern is at certain seasons so completely 

 covered with moths as to obscure the light and to require the attendance of men with 

 brooms. Mr. Tomlinson was informed by the keepers at the Eddystone that bees and 

 other insects were much attracted by the light, and collected round the lantern in great 

 numbers. Larks and other birds flew against it, and, becoming stunned with the blow, 

 were picked up on the balcony and were cooked by the men for breakfast. The lantern 

 is very liable to injury in high winds, or the glass may be broken by large sea-birds 

 coming against it on a stormy night, or by small stones violently driven against it by 

 the wind. Extra plates of glass are always kept to take the place of broken panes. 

 The number of light-keepers employed varies, ranging from two to four, and in the 

 latter case one is usually allowed to remain on shore, the men taking the privilege in 

 turns. When the situation admits, it is usual to have the keeper's rooms in a building 

 outside the lighthouse to avoid dust, which is most injurious to the delicate appai'atus 

 of the light-room. Great cleanliness is enforced in all that belongs to a lighthouse, the 

 reflectors and lenses being constantly burnished, polished, and cleansed. 



And so we have traced the history and progress of lighthouses, and it is hard to 

 believe that any great change can be advantageously made in their construction, though 

 their mode of illumination will doubtless be greatly improved. As we have seen, the 

 electric light was used practically in a lighthouse long before it was in the streets of the 

 great metropolis, and not in a merely experimental way, but with the most successful 

 results. 



