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of Camborne, Cornwall.
Nicholas Holman (1777-1862) had four sons who formed a company that designed and built the Cornish Rock Drill. An example 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.
1801 Company founded. See N. Holman and Sons
1880 Name changed to Holman Brothers
1887 Beam engine for East Pool Mine.
1906 Private company.
1914 Specialities: Mining Machinery of all kinds including Air Compressors, Rock Drills, Pumping and Winding Engines, Ore-dressing Machinery and Boilers. 
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