both of attack and defence. He also made a survey of the place and the military positions in its neighbourhood, and set in hand various works to improve its condition as a commanding post. Towards the end of 1761 Mackellar was appointed chief engineer with the expedition under General Robert Monckton [q. v.], directed against Martinique in the West Indies. The expedition sailed from Barbados on 24 Dec. The first attempt to land failed, and it was not until 16 Jan. 1762 that the expedition disembarked at Point Negro, a few miles from Fort Royal, against which a siege was commenced. Mackellar conducted the siege operations, having under him a small brigade of men who had been instructed at Halifax, and were selected from the various regiments. After a troublesome siege, breaches were made and the place stormed on 4 Feb. 1762. This success was at once followed by the surrender of the whole island of Martinique, and of the other Windward West Indian islands remaining in possession of the French. A series of five plans showing the operations, drawn by Mackellar, is in the British Museum.
On 3 Jan. 1762 Mackellar was promoted lieutenant-colonel, and in May he joined off Cuba, as chief engineer, the force of the Earl of Albemarle, which was destined for an attack on the Havannah. The force landed on 7 June, and after a sharp encounter with a large body of the enemy, advanced to the siege of El Moro, a strong fort which formed one of the main defences of the harbour. The siege was conducted under every possible difficulty—no earth for trenches, no roads to bring up guns, and no water near. On landing, Mackellar improvised a small selected corps for trench work, and their services were invaluable. At this siege every engineering device to circumvent the garrison was employed, and the subterranean galleries and mines were marvels of ingenuity. On 30 July a large breach was made by mines, and the fort was then carried by storm, after an attack of forty-four days. This was followed shortly by the capitulation of the whole island, including the surrender of nine Spanish sail of the line which were in the harbour of the Havannah. Mackellar's conduct of the siege, and particularly in the reduction of El Moro Castle, showed great skill and resource, and gained him a high reputation. His share of prize-money was 564l. 14s. 6d. His journal of the siege was printed in the ‘London Gazette,’ September 1762, and plans of the operations both by sea and land, drawn by him, are in the British Museum. Although greatly exposed during the siege in directing the batteries and mines, he seemed proof against injury until near the end, when he received a dangerous wound from a musket-ball from the Moro, and in September was sent to England. Surgical skill failed to extract the bullet.
On the return of peace in 1763 and the restoration of Minorca to Great Britain, Mackellar was sent thither to take over the fortifications, guns, stores, and munitions of war from the French. This he accomplished on 4 June. On 30 Sept. he was appointed chief engineer at Minorca, with extra pay of thirty shillings a day out of the revenue of the island. He set to work to render Port Mahon impregnable and to improve the city. He constructed new outworks for the castle of St. Philip, enlarged Cala Fort, and extended the underground defences and mines. He also built barracks to afford accommodation for a full-size garrison, and executed numerous improvements both in the city and harbour.
On 29 Aug. 1777 he was promoted to the rank of director of engineers and colonel, but on 22 Oct. 1778, while full of zeal and energy and in the midst of his labours, he died at Minorca. Sixteen plans by Mackellar, dating from 1746 to 1772, relating to the defences of Minorca, Cuba, and Martinique, are in the war office. A plan of Drumsin drawn by him in 1757 when employed in Scotland, one of Quebec and the surrounding country showing the works of attack, and drawings of El Moro and the Havannah, are in the British Museum.
[Royal Engineers Corps Records; Corps Papers; Porter's History of the Corps of Royal Engineers, 1889; Military Library, 1799.]
MACKELVIE, WILLIAM, D.D. (1800–1863), united presbyterian divine, born in Edinburgh, 7 March 1800,was soon left fatherless, and spent his youth at Leith, where he became a draper's apprentice. A visit of the Rev. Leigh Richmond to Leith led Mackelvie to leave the established church of Scotland, with which he had been hitherto connected, to join the associate secession congregation of Kirkgate, under the Rev. Mr. Aitcnison, and to study for the ministry of that church. After the usual course at Edinburgh University and the Theological Secession Hall, Mackelvie in 1827 was licensed to preach by the fresbytery of Stirling and Falkirk. In April 1829 he was called to Balgedie, Kinrossshire, where he was ordained by the Dunfermline presbytery. He was one of the earliest promoters of the union between the secession and relief churches, which was consummated in 1847, and at the request of the united synod he drew up a narrative of
