Demainbray, Stephen Charles

, an ingenious electrician, was born in the parish of St. Martin’s, London, in 1710. His father having escaped from France to Holland, upon the revocation of the edict of Nantes, came over to England with king William. He died soon after the birth of his son, who was brought up by his uncle, an officer in the English service, and page of honour to queen Mary, who placed him at Westminster school. Whilst pursuing his studies there, he boarded in the house of Dr. Desaguliers, who instructed him in the mathematics and natural philosophy. At the age of seventeen, before he had left school, he married; and went to Leyden and followed his studies in the university of that place. In 1740, he began to read lectures in experimental philosophy at Edinburgh, and continued them till he was interrupted by the rebellion. He then took up arms for government, and was a volunteer at the battle of Preston-pans. In 1746, he resumed his lectures, and published his discovery of the effects of electricity upon the growth of vegetables. | This discovery was afterwards claimed by abbé Nollet; but is very properly assigned to Dr. Demainbray by Dr. Priestley, in his “History of Electricity.” In 1749, Dr; Demainbray went to Dublin, where he read his lectures with much success, as he did afterwards in several of the French universities, who honoured him with prize medals, and admitted him into their societies. In 1753, being then at Paris, he was invited over to England, to read a course of lectures to his present majesty (then prince of Wales) and the duke of York. On his return to England he married a second wife, his first wife having died about the year 1750. In 1755 he read a public course of lectures in the concert-room in Panton-street, and in 1757 in Carey-street, opposite Boswell-court. After this he gave private courses to other branches of the royal family; and on the arrival of her present majesty in England, instructed her in experimental philosophy, and natural history. In 1768, he was appointed astronomer to his majesty’s new observatory at Richmond, and adjusted the instruments there in time to observe the transit of Venus, which happened the ensuing year. Dr. Demainbray died at Richmond Feb. 20, 1782, and was interred in the churchyard of Northall, where he had purchased a small estate. ¹