Bartholomew was a Scottish cartographer. He is best known for the development of colour contouring (or hypsometric tints), the system of representing altitudes on a graduated colour scale, with areas of high altitude in shades of brown and areas of low altitude in shades of green. He first showcased his colour contouring system at the Paris Exhibition of 1878; although it initially met with skepticism, it went on to become standard cartographical practice.