Frankland of Thirkleby, Yorkshire, first baronet, squandered the family property and disinherited his eldest son; he represented Northallerton in the parliaments of 1713, 1714, 1722, and 1727. William, second son of this Leonard, and father of the subject of this memoir, was member for Northallerton in the parliament of 1734, became receiver of his majesty's casual customs of Barbados (1746), died on 14 Sept. 1755, aged 66, and was buried in the family vault in the chantry chapel in the north aisle of Kirkby Fleetham church.
Leonard, born about 1719, was appointed a clerk in the ordnance office in June 1734. On 1 Jan. 1739 he became a cadet gunner, and, when not engaged in his artillery duties, was permitted to attend the drawing room in the Tower of London, where, under Lempriere and Desmaretz, he acquired considerable skill in the art of military sketching and plan drawing. In April 1741 the Duke of Montagu, master-general of the ordnance, placed Smelt for practical training under the orders of Colonel Lascelles, chief engineer at Portsmouth. In the following June Lascelles recommended him to the duke for the rank of practitioner engineer, and from 13 Aug. 1741 he was employed for nearly a year at the Tower of London under General John Armstrong, chief engineer of Great Britain.
On 19 June 1742 Smelt was one of the ordnance train appointed for active service in Flanders. He served at Dettingen (16 June 1743), and wintered that year at Ghent. On 8 March 1744 he was promoted to be engineer extraordinary, passing over the intermediate grade of sub-engineer. On 30 April 1745 he was at the battle of Fontenoy, and was afterwards employed with Captain Thomas of the engineers, under the Duke of Cumberland, to repair and extend the fortifications of the castle of Vilvorden. A plan of this castle, with the new fortifications, drawn by Smelt and Thomas, is in the British Museum.
On Smelt's return to England towards the end of 1745 he was immediately sent off to the northern district to join the reserves of the force operating against the Jacobite rebels. He was promoted to be engineer in ordinary on 3 Jan. 1747, and in 1749 was employed to survey and afterwards to superintend the construction of a military road between Carlisle and Newcastle-on-Tyne.
In 1751 Smelt was selected ‘as an able engineer, independent in his opinions and bold in expressing them,’ to go to Newfoundland to survey and report on its defences. The colonists desired to have every place defended, especially Placentia. Smelt's reports, dated 22 Nov. 1751, considered that money would be thrown away on defences at Placentia, as the position was not a good one (cf. manuscript report in Brit. Mus.). He proposed to limit defence to a few carefully selected places. After repairing defence works which he considered indispensable, he returned to England in 1752, and was appointed to the western district and stationed at Plymouth.
On the death early in 1753 of Smelt's friend, Captain Kane William Horneck of the royal engineers, grandson of Anthony Horneck [q. v.], he wrote from Horneck's memoranda and sketches an interesting report on the defences of Antigua in the West Indies, which Horneck had recently inspected. Through Horneck's widow, who belonged to a Devonshire family, Smelt made the acquaintance of Joshua Reynolds [q. v.], and sat to him for his portrait in August 1755. On 14 May 1757 he was gazetted captain, and, as engineer in charge of the northern military district, was employed upon the defences of the Tyne—Clifford's Fort and Tynemouth Castle—at the mouth of the river.
In 1770 Robert D'Arcy, fourth earl of Holderness [q. v.], an old friend and neighbour of Smelt, introduced him to the king, who took a great liking for him, despite the fact that he was a ‘revolutionary whig;’ and in April 1771, when Holderness was appointed governor, Smelt was appointed deputy-governor to the Prince of Wales and Frederick, duke of York. He resigned the post after ten years' tenure, in consequence of an intrigue against his patron Holderness, from whom he refused to dissociate himself. He declined a pension, but was subsequently appointed deputy-ranger of Richmond Park, and remained on confidential terms with both the king and queen.
Thenceforth Smelt passed much time in London literary society. From 1787 to 1789 he resided at Kew, where he was frequently with Miss Burney, an intimate friend of himself and his family, and occasionally saw and conversed with the king during his illness in the winter of 1788–9. In 1792, shortly after the death of his wife, Smelt gave up society, relinquished his house on the Thames, and went to Yorkshire, where he died at Langton on 2 Sept. 1800.
Smelt was long popular in a society which included Dr. Johnson, Goldsmith, Reynolds, the Garricks, the Burkes, Mrs. Montagu, Hannah More, the Burneys, and others. Of polished manners, with a cultivated mind and a taste both for art and literature, he was a general favourite in what was known as the blue-stocking circle. Mrs. Delany praised him highly, and Horace Walpole approved of him without reserve; but it is pro-
