is the taking or finding the integral or fluent again from the fluxion. See Fluxions, Encycl.

REFLECTOR for a light-house, is composed of a number of square plane glass mirrors, similar to those with which Archimedes is said to have set fire to the Roman fleet at the siege of Syracuse (See Burning, Encycl.) Each of these mirrors is about an inch square; and they are all disposed close to each other in the concave of a parabolic segment, formed of stucco or any other proper bed. Stucco has been found to answer the purpose best; and is accordingly employed in all the reflectors of the light-houses erected by Mr Thomas Smith, the builder, Edinburgh, at the expense, and by the authority, of government. This ingenious and modest man seems to have conceived the idea of illuminating light-houses by means of lamps and reflectors instead of coal-fires, without knowing that something of the same kind had been long used in France; he has therefore all the merit of an inventor, and what he invented he has carried to a high degree of perfection.

His parabolic moulds are from three to five or six feet in diameter; and in the centre or apex of each is placed a long shallow lamp of tin plate, filled with whale oil. In each lamp are six cotton wicks, almost contiguous to each other, which are disposed as to burn without trimming for about six hours. The light of these is reflected from each mirror spread over the concave surface, and is thus multiplied, as it were, by the number of mirrors. The stucco moulding is covered on the back with tin-plate, from which a tube immediately over the lamp proceeds to the roof of the