1853 and 1858, adding to the idea of separate blades and less vibration still further efficiency and reduction in cost. An improved form of 'protector' was Griffiths's last patent of note, though in 1878 he invented a serviceable plan of placing the screw propeller a distance equal to two-thirds of its diameter aft the end of the run. Griffiths secured other patents for an electric hair brush, intended to prevent hair turning white; supplementary improvements in bolt and rivet making; and an automatic damper for steam boilers, as well as a method of preventing scale in boilers, the two latter protectors being obtained jointly with Mr. C. W. Copeland. Griffiths read a number of valuable papers before the Society of Naval Architects and at the Royal United Service Institution, chiefly relating to his own original experiments. He died in June 1883.
[Memoir in Engineering, 29 June 1883.]
GRIFFITHS, THOMAS, D.D. (1791–1847), Roman catholic prelate, born in London 2 June 1791, was educated in the doctrines of the English church, but was converted to Catholicism by his mother, and sent in 1805 to St. Edmund's College, Old Hall Green, near Ware. In July 1814 he was ordained priest, and for the next four years he presided over the small ecclesiastical seminary in the 'Old Hall' in the rear of the college. In 1818 he removed with the students to the new college, of which he was appointed president in succession to Dr. Bew. For more than fifteen years he governed St. Edmund's with remarkable prudence. On the death of Bishop Gradwell he was appointed in July 1833 coadjutor, with the right of succession, to Bishop Bramston, vicar-apostolic of the London district, and he was consecrated on 28 Oct. at St. Edmund's College to the see of Olena in partibus. He succeeded to the London district on the death of Bishop Bramston, 11 July 1836. In 1840 Pope Gregory XVI increased the number of vicariates in England, and Griffiths was appointed by letters apostolic, dated 3 July, to the new London district. He entered into communication with the government on matters relating to the Roman catholic church in the colonies. He died at his residence in Golden Square, London, on 12 Aug. 1847, and was buried at St. Mary's, Moorfields.
Several of his Lenten pastorals and his funeral discourse on Dr. Robert Gradwell [q. v.], bishop of Lydda, have been published. There is a portrait of him, engraved by G. A. Peria, in the 'Catholic Directory' for 1848.
[Brady's Episcopal Succession, iii. 200; Catholic Directory, 1848, p. 126; Dolman's Magazine, vi. 199-207; Gent. Mag. 1847, pt. ii. 439; Gillow's Bibl. Dict. iii. 61.]
GRIGNION or GRIGNON, CHARLES (1754–1804), painter, born in 1754 in Russell Street, Covent Garden, was younger son of Thomas Grignion, a well-known watchmaker in that street, and was nephew of Charles Grignion (1717-1810) [q. v.] In 1705 he obtained a premium at the Society of Arts for a drawing by boys under fourteen, and in 1768 a silver palette for a drawing of the human figure. He was a pupil of Cipriani, and one of the earliest students at the Royal Academy, where in 1776 he obtained the gold medal for an historical picture of 'The Judgment of Hercules,' and in 1782 the travelling pension awarded by the Royal Academy to enable students to go to Rome. In 1770, while a pupil of Cipriani, he exhibited a head in oils at the Academy, and in 1771 and the ten following years, while residing with his father, continued to exhibit portraits and, occasionally, mythological subjects. In 1782 he proceeded to Rome, and in 1784 sent to England a large picture of 'Captain Cook attacked by the Natives of Owyhee in the South Seas, 14 Feb. 1779.' In 1791 he was practising as a history and portrait painter in the Strada Laurina, Rome. He produced many works of excellence, several of which he sent to England. Lord Nelson sat to him for his portrait at Palermo in 1798. During the French invasion he was instrumental in saving many pictures from plunder or destruction, notably the so-called 'Altieri' Claudes. On the French entering Rome he was compelled to retire to Leghorn, where he was attacked by fever, and died on 4 Nov. 1804. He was buried in the British cemetery there. Two drawings by him were engraved, 'An Assassination near the Porta del Popolo' and 'Peasants dancing the Saltarella.' They had been purchased of the artist in Rome by Lord Clive. A drawing of Captain George Farmer (engraved in mezzotint by Murphy) is in the print room at the British Museum.
[Edwards's Anecdotes of Painters; Redgrave's Dict. of Artists; J. T. Smith's Nollekens and his Times; Roy. Acad. Catalogues.]
GRIGNION or GRIGNON, CHARLES (1717–1810), line-engraver, born in Russell Street, Covent Garden, on 25 Oct. 1717, was son of a foreigner and apparently a brother of Thomas Grignion, a well-known watchmaker in that street. He studied as a boy under Hubert François Gravelot [q. v.], and at the age of sixteen went to work under J. P. Le Bas in Paris, where he remained six months. He then returned to London, resumed work under
