"...much patronized, on account of his mathematical knowledge, by the late Lord Seaforth and my late grandfather, Francis, the fifth Lord Napier of Merchistoun. He was for some time employed by the latter, who was about to write a life of his ancestor John Napier, of Merchistoun, the inventor of logarithms, to collect for him... [information] from all the different works relative to India, an account of the knowledge which the Hindoos possessed on mathematics, and of the nature and use of logarithms. Mr Mackenzie, after the death of Lord Napier, became very desirous of prosecuting his Oriental researches in India. Lord Seaforth, therefore, at his request, got him appointed to the engineers on the Madras establishment."