MR. Clark was born at Great Marlow in 1822, and probably acquired his scientific bent while engaged at a manufacturing chemist's business in Dublin. On the outbreak of the railway mania in 1845 he took to surveying, and through his brother, Mr. Edwin Clark, became assistant engineer to the late Robert Stephenson on the Britannia Bridge. While thus employed, he made the acquaintance of Mr. Ricardo, founder of the Electric Telegraph Company, and joined that Company as an engineer in 1850. He rose to be chief engineer in 1854, and held the post till 1861, when he entered into a partnership with Mr. Charles T. Bright. Prior to this, he had made several original researches; in 1853, he found that the retardation of current on insulated wires was independent of the strength of current, and his experiments formed the subject of a Friday evening lecture by Faraday at the Royal Institution—a sufficient mark of their importance.

In 1854 he introduced the pneumatic dispatch into London, and, in 1856, he patented his well-known double-cup insulator. In 1858, he and Mr. Bright produced the material known as 'Clark's Compound,' which is so valuable for protecting submarine cables from rusting in the sea-water. In 1859, Mr. Clark was appointed engineer to the Atlantic Telegraph Company which tried to lay an Anglo-American cable in 1865. in partnership with Sir C. T. Bright, who had taken part in the first Atlantic cable expedition, Mr. Clark laid a cable for the Indian Government in the Red Sea, in order to establish a telegraph to India. In 1886, the partnership ceased; but, in 1869, Mr Clark went out to the Persian Gulf to lay a second cable there. Here he was nearly lost in the shipwreck of the Carnatic on the Island of Shadwan in the Red Sea.

Subsequently Mr. Clark became the head of a firm of consulting electricians, well known under the title of Clark, Forde and Company, and latterly including the late Mr. C. Hockin and Mr. Herbert Taylor.

The Mediterranean cable to India, the East Indian Archipelago cable to Australia, the Brazilian Atlantic cables were all laid under the supervision of this firm. Mr. Clark is now in partnership with Mr. Stanfield, and is the joint-inventor of Clark and Stanfield's circular floating dock. He is also head of the well-known firm of electrical manufacturers, Messrs. Latimer Clark, Muirhead and Co., of Regency Street, Westminster.

The foregoing sketch is but an imperfect outline of a very successful life. `But enough has been given to show that we have here an engineer of various and even brilliant gifts. Mr. Clark has applied himself in divers directions, and never applied himself in vain. There is always some practical result to show which will be useful to others. In technical literature he published a description of the Conway and Britannia Tubular Bridges as long ago as 1849. There is a valuable communication of his in the Board of Trade Blue Rook on Submarine Cables. In 1868, he issued a useful work on ELECTRICAL MEASUREMENTS, and in 1871 joined with Mr. Robert Sabine in producing the well-known ELECTRICAL TABLES AND FORMULAE, a work which was for a long time the electrician's VADE-MECUM. In 1873, he communicated a lengthy paper on the NEW STANDARD OF ELECTROMOTIVE POWER now known as CLARK'S STANDARD CELL; and quite recently he published a treatise on the USE OF THE TRANSIT INSTRUMENT.

Mr. Clark is a Fellow of the Royal Society of London, as well as a member of the Institution of Civil Engineers, the Royal Astronomical Society, the Physical Society, etc., and was elected fourth President of the Society of Telegraph Engineers and of Electricians, now the Institution of Electrical Engineers.

He is a great lover of books and gardening—two antithetical hobbies—which are charming in themselves, and healthily counteractive. The rich and splendid library of electrical works which he is forming, has been munificently presented to the Institution of Electrical Engineers.