Captain Henry Kater, distinguished by his mathematical and physical researches during the space of nearly half a century, was born at Bristol; his father was of a German family, and his mother was the daughter of an eminent architect; both were distinguished for their scientific attainments, and united in imbuing their son with a similar taste. Henry was, however, destined by his father for the law, and had with great reluctance to give up for a time his hitherto exclusive devotion to abstract science. Mr. Kater continued for two years to remain in a pleader's office, during which time he acquired a considerable portion of legal knowledge, on which he valued himself through life; but the death of his father, in 1794, permitted him to resume his favourite studies; and bidding adieu to the law, he obtained a commission in the 12th Regiment of Foot, at that time stationed in India. During the following year, Mr. Kater was engaged in the trigonometrical survey of India under Colonel Lambton, contributing greatly, by his untiring labours, to the success of that vast undertaking. About the same period, he was also occupied in constructing a peculiarly sensible hygrometer, of which he published a description in the 'Asiatic Researches.' Mr. Kater remained in India seven years, during which time his unremitting study in a hot climate greatly injured his constitution, and was the cause of his falling into a state of ill health, from which he suffered more or less until the end of his life.