H is for Holman, the man with the drill. In the 19th century Cornwall was the world's leading centre for the development and manufacture of equipment for the mining industry. The development of the rock drill for boring holes in rock, was led by the Camborne engineering company of Holman Brothers.

Holman had been a blacksmith who assisted the father of the locomotive, Richard Trevithick of Camborn, with the development of his early high pressure steam boilers.

Holman Bros, Camborne, made their first patented compressed air drill in 1881. Before this all drilling was done by hand. Holman drills were synonymous with mining and won many competitions, and held a number of mining and tunneling world records.

Through various mergers Holman's eventually became Comp Air Ltd. They ceased operation in 2003.