For burnishing the reflectors, prepared _rouge_ (tritoxide of iron) of the finest description, which should be prepared in the state of an impalpable powder of a deep orange-red colour, is applied by means of soft chamois skins, as occasion may require; but the great art of keeping reflectors clean consists in the daily patient and skilful application of manual labour in rubbing the surface of the instrument with a perfectly dry, soft, and clean skin, without rouge. The form of the hollow paraboloid is such that some practice is necessary in order to acquire a free movement of the hand in rubbing reflectors; and its attainment forms one of the principal lessons in the course of the preliminary instruction to which candidates for the situation of a lighthouse-keeper are subjected. For cleansing the lenses and glass-mirrors spirit of wine is used. Having washed the surface of the instrument with a linen cloth steeped in spirit of wine, it is carefully dried with a soft and dry linen rubber, and finally rubbed with a fine chamois skin free from any dust, which would injure the polish of the glass, as well as from grease. It is sometimes necessary to use a little fine rouge with a chamois skin for restoring any deficiency of polish which may occur from time to time; but in a well-managed lighthouse this application will seldom, if ever, be required. * * * * * Before we quit this subject, it may interest the reader to be informed that the glass of the lantern is frequently broken, not by wind and wave, but by the sea-birds which dash violently against it. In a single night at Cape de Bréhat nine panes were shattered from this cause. At the lighthouse of Bréhat a wild duck forced its way through two rows of mirrors and fell upon the lamp. A thousand of these birds were on one occasion caught by the crew of a British lightship, who made them into a gigantic pie. It is necessary to defend with trellis-work the lights most exposed to visits of this kind. [Illustration: SEA-BIRDS ATTRACTED BY THE RAYS OF A LIGHTHOUSE.] Fortunately, all sea-birds are not so dangerous. Some of them even render to the navigator a service like that which the goose of the capitol, according to Livy, once rendered to the Romans. At the South Stock lighthouse, near Holyhead, which is situated in the middle of an islet, tamed sea-birds are made use of as signals. The gulls perch on the lighthouse walls and utter loud cries, which wave off approaching seamen. This lighthouse possesses a bell and a cannon, but the natural signal has been esteemed so superior that the cannon has been removed to a distance from the rock, lest its discharge should alarm the birds. The young gulls roam about the island among the white rabbits, living in perfect harmony with them, and providing the keepers with society; a pleasanter society than that of the wind and waves which incessantly vent their fury on the solitary pharos. [Illustration] [Illustration]