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of Camborne, Cornwall.
Cornish manufacturers pioneered dust suppression in mining by delivering a water spray to the drill tip which also had the benefit of providing lubrication. One of the major manufacturers was Camborne-based Holman Brothers which, with James McCulloch, developed what became known as the Cornish Rock Drill. It was to see use in South Wheal Crofty, Dolcoath Mine, Tincroft Mine, East Pool Mine, Kit Hill, and also mines in Wales by 1882.
An example of the Cornish Rock Drill is in the Cornwall Museum at Truro. They were designed to drill vertical holes supported by an internal airleg, that pushes the drill bit upwards. Its maximum extension was 60 cms (2ft), so to drill a 1.8 metre hole, three different drill-steels of 60cms, 120 cms and 180cms were required. They could achieve approximately 30 cms per minute and weighed about 45 Kg.
1887 Supplied beam engine for East Pool Mine.
John Holman was succeeded by John Henry Holman
1906 Incorporated as a limited company - Holman Brothers
1914 Directors: James Miners Holman (Managing Director), and J. Leonard Holman
1914 Specialities: Mining Machinery of all kinds including Air Compressors, Rock Drills, Pumping and Winding Engines, Ore-dressing Machinery and Boilers. 
1922 Directors: James Miners Holman (Managing), John Leonard Holman, Arthur Treve Holman and Percy Mynors Holman. Manufacturer of air compressors, rock drills, drill sharpeners, haulages, concentrators, general mining and quarrying plant, pneumatic tools.
1937 Pneumatic tool and plant manufacturers. "Rotodrill" Pneumatic Drills and "Rotogrind" Pneumatic Grinders. 
1951 Acquired an interest in Climax Rock Drill and Engineering Works
1957 About two-thirds of Climax's equity was owned by Holman Brothers
1960 Rock drills, air compressors and other tools. (Of Camborne). 
1961 Mining and civil engineering equipment manufacturers. 2,500 employees.
1961 Sales of Maxam Power automation and control systems, Goodyear Pumps and Rotair screw compressors
1968 Merger of Broom and Wade and Holman Brothers, with the encouragement of the Industrial Reorganisation Corporation, to form the International Compressed Air Corporation with principal tradenames Broomwade, Holman and Maxam
An excellent illustrated history of the company is available, first published in 2001