# Dictionary of National Biography, 1885-1900/Mackellar, Patrick

​MACKELLAR, PATRICK (1717–1778), colonel, military engineer, belonged to an old Scottish family. In 1735 he entered the ordnance service as a clerk at Woolwich, and in 1739, having been promoted to the office of clerk of the works, was sent to Minorca, at that time a military station of equal importance with Gibraltar. His talent for architecture and military engineering gained him on 7 Dec. 1742 the warrant of practitioner engineer, and on 8 March 1743 he was promoted to be engineer extraordinary, without passing through the intermediate rank of sub-engineer. In 1751 he was promoted engineer in ordinary. With the exception of a short interval of special duty at Sheerness in 1752, he remained at Minorca until 1754, his duties consisting in perfecting the defences of Port Mahon, with the collateral work of St. Philip's Castle, and in the extension of the subterranean mine defence, and of the underground stores and magazines, designed by Brigadiers Petit and Durand.
In 1754 Mackellar was called home to join the expeditionary force to North America, and served in the ill-fated campaign under Braddock, making roads and bridges in advance of the army on the march from Alexandria in Virginia across the Alleghany mountains, through a wild and little known ​country to Fort Du Quesne, at the junction of the Ohio and Monongahela rivers. The army was surprised by the French and their Indian allies on 11 July and nearly cut to pieces. Mackellar was severely wounded, and lost his horse and baggage, for which he eventually received 183l. as compensation.
In the spring of 1756 he was made chief engineer of the frontier forts, and was engaged in the construction of two new forts to supersede those existing at Ontario and Oswego when, in August, the enemy's appearance compelled the British troops to retire into the old forts. These Mackellar put into repair as rapidly as possible, and conducted the defence with ability. The siege of Ontario was short and decisive; the old walls broke up at every blow from a missile. The garrison abandoned the work, and crossing the water pushed into the scarcely tenable fort of Oswego. Here again Mackellar did his best, but the garrison was forced to capitulate, and Mackellar became a prisoner of war. He was taken to Quebec, and thence to Montreal. Although kept in somewhat close restraint, he managed to learn many useful particulars about the places which he was afterwards to assault. On the exchange of prisoners in 1757 he returned home, and was employed in repairing the castles, forts, and batteries in Scotland. On 14 May 1757 he was commissioned captain in the army in addition to his ordnance rank of engineer, and on 4 Jan. 1758 he was promoted sub-director and major. Mackellar was second engineer, Bastide being the chief, in the expedition under Jeffrey, afterwards baron Amherst [q. v.], for the reduction of Louisburg, which left Halifax on 28 May 1758. They arrived at Cape Breton on 2 June, and disembarked successfully on the 8th in the face of an obstinate resistance. Lighthouse Point was seized on the 12th. The camp was entrenched and ground broken against the fortress of Louisburg by Mackellar the same night. In one of the sorties Bastide, who had been wounded the previous day, was taken prisoner, and Mackellar assumed the chief conduct of the operation. The English fire soon became so hot that three of the largest of the enemy's ships were set ablaze, the approaches were driven closer and lodgments formed in the advanced works, while the citadel was in flames. On 27 July the garrison (6,537 strong), without awaiting the assault, laid down their arms. With the capture of Louisburg the whole island of Cape Breton fell to the British, whose loss was only 523 killed and wounded. Wolfe, who was present as brigadier-general, abused the chief engineer for taking so long over the business, but the success of the undertaking with so small a loss was a laurel for Mackellar.
On 13 May 1759 Wolfe, who had been appointed to the supreme command of the land forces in North America, sailed for the St. Lawrence, and took Mackellar as his chief engineer. The expedition arrived at the island of Orleans, opposite Quebec, on 26 June. Mackellar threw up batteries both on the west front of the island and also at Point Levi, and on 10 July opened fire on both the upper and lower towns of Quebec. The lower town was soon reduced to ruins, but little impression was made on the upper, and Wolfe, growing impatient, made an attack in force from Montmorency on 31 July, during which Mackellar was severely wounded. The attempt failed, and Mackellar, notwithstanding his wound, continued to direct the siege operations. Wolfe was eager to storm, but was dissuaded by Mackellar, who knew from observations, made when a prisoner, the many obstacles that must interpose between the assault on the walls and the capture of the citadel. On 13 Sept. Wolfe attacked the city from above, and Mackellar was with him when he fell on the heights of Abraham. The city still held out, and Mackellar broke ground for a regular attack from the favourable position gained by the British. On 17 Sept. the French capitulated. A journal of the expedition signed ‘P. M.,’ and written it is believed by Mackellar, is printed in the ‘Corps Papers of the Royal Engineers,’ 1847, contributed by Lieutenant-general G. G. Lewis [q. v.], by whom, however, it is wrongly attributed to Major James Moncrieff [q. v.] of the engineers, who was not commissioned until 1762. Mackellar remained as chief engineer with Brigadier-general James Murray (1720–1794) [q. v.], who took command of the city, and during the autumn and spring he strengthened the fortifications. In April 1760 the French, ten thousand strong, advanced on Quebec. Murray met them at Sillery, with Mackellar in command of his artillery. Murray was defeated and driven back to Quebec, and Mackellar was dangerously wounded. The French besieged Quebec, and Mackellar, as soon as he was convalescent, directed the defence until the advance of the British fleet up the St. Lawrence caused the siege to be raised. Mackellar took part in the various services undertaken this year to complete the conquest of Canada, ending with the capture of Montreal. He then accompanied the army to Halifax, Nova Scotia, which had become a large depôt and arsenal. On 24 Nov. 1760 he was appointed chief engineer at Halifax, and while at that station he was indefatigable in instructing the troops in siege operations, ​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.]
R. H. V.