Faraday’s work for Trinity House continued during these last years of research work. He reported on such subjects as adulteration of white lead, impure oils, Chance’s lenses, lighthouse ventilation, and fog signals. Two systems of electric arc lighting for lighthouses--one by Watson, using batteries, the other by Holmes, using a magneto-electric machine--were examined in 1853 and 1854, but his report on them was adverse. He “could not put up in a lighthouse what has not been established beforehand, and is only experimental.” In 1856 he made five reports, in 1857 six, and in 1858 twelve reports to Trinity House, one of these being on the electric light at the South Foreland. In 1859 he reported on further trials in which Duboscq’s lamps were used. In 1860 he gave a final report on the practicability and utility of magneto-electric lighting, and expressed the hope it would be applied, as there was _now_ no difficulty. In 1861 he inspected the machinery as established at the Dungeness lighthouse. In 1862 he gave no fewer than seventeen reports, visiting Dungeness, Grisnez, and the South Foreland. In 1863 he again visited Dungeness. In 1864 he made twelve reports, and examined the drawings and estimates for establishing the electric light at Portland. His last report was in 1865, upon the St. Bees’ light, and he then retired from this service. His Friday night discourses were still continued during these years. In 1855 he gave one on “Ruhmkorff’s Induction-coil.” In 1856 he gave one on a process for silvering glass, and on finely divided gold. This latter subject, the optical properties of precipitated gold, formed the topic of the Bakerian lecture of that year--his last contribution to the Royal Society. He gave another discourse on the same subject in 1857, and also one on the conservation of force. In 1856, when investigating the crystallisation of water, he discovered the phenomenon of regelation of ice. In virtue of this property two pieces of ice will freeze solidly together under pressure, even when the temperature of the surrounding atmosphere is above the freezing point. This discovery led on the one hand to the explanation of glacier motions; on the other to important results in thermodynamic theory. In 1859 he gave two discourses, one on ozone, the other on phosphorescence and fluorescence. He also gave two in 1860, on lighthouse illumination by electric light, and on the electric silk-loom. In 1861 he discoursed on platinum and on De la Rue’s eclipse photographs. The last of his Friday night discourses was given on June 20th, 1862. It was on Siemens’s gas furnaces. He had been down at Swansea watching the furnaces in operation, and now proposed to describe their principle. It was rather a sad occasion, for it was but too evident that his powers were fast waning. Early in the evening he had the misfortune to burn the notes he had prepared, and became confused. He concluded with a