s surveyor with the army, Mackenzie himself made many topographical and military drawings, including 'one of Tippoo's gallopers on its Carriage at Shirkapoor 3rd January 1806' and views of Nandidrug, Savandrug and plans of Tipu forts. After the siege of Nandidrug, Mackenzie was applauded in the Calcutta Gazette for his 'skill and indefatigable industry,' and congratulated by Lord Cornwallis for his part in determining the position of the batteries, which are shown blazing fiercely in Mackenzie's watercolour of the attack. Mackenzie's collection of drawings also included the plan of a carriage for lifting heavy stones; a plan of Mackenzie's house at Madras; a view of the Mosque at Seringapatam in July 1799; a map of the Island of Lewis and a Map of the 'Long Isle, North Briton' (i.e. Scotland), Mackenzie's native land.

The logistical problems involved in conducting military campaigns many thousands of miles from home are a constant topic in the literature of the Mysore Wars. Each 12-18 pounder brass gun required relays of 28-70 bullocks to drag it along, and 24 pounder iron guns required as many as 70 beasts per gun. Major Dirom notes the 'skill and great labour' necessary to drag guns up and through the Pednaidurgam Pass, 7 miles North of Ounoor, These passages were often rendered even more difficult by rains and bad roads, and Dirom mentions that the draft and carriage cattle 'always die in vast numbers when exposed to wet and fatigue.'