Politician, artist and author. Born at Penicuik, the son of the wealthy Sir John Clerk (1676 - 1755), Clerk had business interests in Edinburgh and went on to take various positions in government. He wrote a controversial essay on naval tactics (1782) but is perhaps best known as a prodigious amateur artist at the time of the Scottish Enlightenment. Clerk accompanied architect Robert Adam (1728-92) on drawing trips and married Susannah, Adam's younger sister. He sketched around Edinburgh with Jacob More (1740-93) and Alexander Runciman (1736-85), and was deeply interested in portraying Scottish landscapes and architecture. He produced drawings to illustrate the important The Theory of the Earth written by his friend James Hutton (1726-97).
He lived at Eldin House (now Nazareth House, Lasswade), where he died.