Along side the mining industry has grow up an industry manufacturing specialised mining equipment.

An early rock drill development was the Macdermot and Glover Patent Percussive Rock Perforator.

Holman Bros Camborne Cornwall.

The firms founder Nicholas Holman started a boiler works in 1801

Drills.

1881-The brothers John Henry and James Miners Holman, who had taken over running the business from their father John, were offered the designs of a new rock drill by a Scotsman, James McCulloch. the brothers were enthusiastic, filed a joint patent with McCulloch, and began to manufacture the new drill. It soon became known as the Cornish Rock Drill, and achieved great success.

1882-The rock drill was at work at Dolcoath, Tincroft, East Pool, South Crofty, at Falmouth Docks and in mines in South Wales.

The demand for rock drills in Britain and abroad grew rapidly.

1896-More than 1,000 Cornish rock drills were in use on The Rand alone.

By the turn of the century the number had doubled. Most of these drills came from Holman in Camborne.

1910-The company took first and third prizes in a World Rock Drilling Contest, sponsored by the South African Chamber of Commerce.

The earlier rock drills createda dust hazard, causing silicosis. To reduce the airborne dust, the Cornish miners would pour water over the drill head. It was Leyner who introduced the water tube into the drill, adopting at the same time as he developed the hammer drill.

The first successful drills were the piston type, or "reciprocators." The drill steel piston and chuck moved together and reciprocated. In Leyner's hammer drill the steel was held loosely in a chuck attached to the cylinder itself, while the piston inside the cylinder reciprocated, striking blows on the blunt end of the drill steel. The hammer drill was lighter, speedier, and used less air than the reciprocating drill.

Leyners earlier drills used a blast of air blown through a hollowed or channelled drill steel to keep the drill holes clear of rock chippings: these drills, however, raised too much dust. To overcome this Leyner introduced water along the drill together with the blast of air. This machine soon ousted the previous one, and was taken up by the Holman factory on a large scale.

Another Holman model of interest is the Holman Silver 303 Airleg used all over the world for mine development.

Compressors.

Holman began to manufacture compressors some time before they took up rock drills. The first "Cornish" compressors were built to designs adapted from existing steam engines.

1894-Holman manufactured the largest compressor plant ever used in Cornwall. Installed at Carn Brea Mine.

1959-Holman introduced the Rotair, Britain's first single stage oil flooded rotary screw compressor.

1964-Launched Britains first range of portable compressors.

1968-A merger took place with Broom and Wade to form CompAir-the International Compressed Air Corporation Ltd.

Today a very scaled down factory still manufactures compressors using part of the old factory site in Camborne.