By the mid 1870s there were 400 people working on Hingston Down, digging the clay and working the kilns and it was difficult to keep up with demand. Linings for Admiralty furnaces, gas retorts, crucibles and heavy duty blue bricks were produced along with vitrified paving bricks and terra cotta tiles.

Initially the clay was moulded by hand into bricks, but later this was done by steam powered mills which extruded long strips which had to be cut to size using a wire. After being left to dry, they were fired in a kiln at 1000º C for 4 days and then left to cool for a further 5 to 8 days
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There were ten brickmaking companies in the parish:

SX435713 Bealswood Brickworks
SX412715 Calstock Firebrick Company
SX432688 Calstock Town
SX426717 Old Dimson Brickworks
SX420717 Greenhill
SX408719 Chilsworthy
SX395715 Phoenix Vitrified Paving and Firebrick Works
SX426729 Plymouth Works
SX425711 Sandhill
SX400717 Tamar Firebrick and Clay Company

Bealswood Brickworks
This opened around 1850 becoming the largest brickworks in Cornwall. It closed in 1914, although it was active in a small way in the 1930s. It was owned by Thomas Westlake. There were five rectangular kilns plus a Hoffman kiln producing (red bricks and) blue heavy duty bricks which were advertised at 35s (£1.75) a thousand in 1857. As the works fronted the River Tamar, bricks could be loaded straight onto barges. The site is now boggy and the buildings collapsed and overgrown. Remains of four kilns, a square chimney stack and an engine house can be seen.

Calstock Town Brickworks
A brickworks is shown on the 1839 tithe map. A large building in Calstock for manufacturing coarse earthenware or bricks was advertised to let in The Sherborne Mercury in 1781. By 1856 the brickworks was listed in Kelly’s Directory run by John Westlake. The Westlakes ran it until the First World War using clay from Greenhill. There were two beehive kilns. By 1955 the site was occupied by the Chip Factory which made baskets for fruit. This closed in 1983 and the site is now occupied by houses.

Calstock Firebrick Company
The works were on Hingston Down. The company was started by Thomas Westlake in about 1860 and was taken over by the West of England Fireclay, Bitumen and Chemical Co Ltd in 1871. It was noted in Kelly’s directory in 1873. There were four beehive kilns producing earthenware pots, cloam ovens and white firebricks. These were all demolished in 1968 and sold for hardcore. In 1877 the roof of the engine house and grinding shed were blown off by the gale causing it to close temporarily. In Kelly’s 1893 it was owned by Thomas Cuthbert Franks with William Burnham as manager. It closed around 1906.

Old Dimson Brickworks
Little is known about this brickworks. Fields called Brick Kiln and Clay Field along with two circles, possibly beehive kilns and buildings, appear on the 1839 tithe map but there is no clay pit. These were owned by Rev Beauford and rented by Mary Bowhay. According to the 1856 trade directory, her son Joseph was a brickmaker and farmer. By 1872 he no longer made bricks and there are no buildings 1880 ordnance survey map.

Greenhill and Chilsworthy Works
Both the Greenhill Fire Brick and Clay Co and Greenhill Arsenic Works were owned by the Cornwall Chemical Company, the two works being separated by the Drakewalls-Chilsworthy road over which an incline tramway crossed to connect the two works. It was opened about 1873 using Batchelor kilns and later eight beehive kilns all of which have been demolished. The clay pit was to the north west. The works were later taken over by the West of England Fire Clay & Bitumen & Chemical Co Ltd with William Jones as manager. In 1894 Moses Bawden owned Greenhill. The works were taken over by Hill Westlake and some time between 1907 and 1919 a new works, Chilsworthy Works, was built the other side of the clay pit. Three rectangular kilns and a Scrivener beehive kiln were built but there is no evidence that they were connected to a flue and were possibly never used. Two rectangular kilns and the beehive kiln still survive and are in the grounds of Plastech Ltd. A tramway brought the clay across the road and into the works. The girders for the overhead tramway could be seen going across the road until removal in 2006. A railway siding to this brickworks was built in 1914, the buildings were used for storage in 1942 and the track removed in 1959.

Phoenix Vitrified Paving and Firebrick Works
Opened in 1874 but lasted only 9 years, production being transferred to the company’s other works in Wellington. They produced white and blue bricks with a glazed finish and terracotta tiles and traded extensively with the Russians. Examples can be seen on Vennings Fountain which is between Callington and Kelly Bray on the Callington-Launceston Road. There were five beehive kilns, the clay coming from nearby pits.

Plymouth Works
This works appears to have had several names and owners. In 1873 it was the Dimson Fireclay Co managed by Samuel Lake. From 1883-89 it was the Plymouth Fireclay Co managed by A.H. Bates. Firebricks were made. They used a large circular Hoffman kiln which has now been demolished. A house beside the entrance to the works is possibly the yard office or
manager’s house and the buttresses which carried the tramway over the road can still be seen

Tamar Firebrick and Clay Company
Opened in April 1871 after 20 acres of land had been acquired by Thomas Procter and Samuel Richards,a mining engineer. The company was registered with a capital of £20,000, shares being £2 each. In 1880 some of the products were used in the building of the Plymouth Public school. The works had closed down by 1887 when Charles Edward Appleby was the proprietor (or was it 1914). The company was restarted around 1918 with Thomas Hill as manager. Westbrick Co bought it in 1918 and it closed down in the same year (and closed in 1935 by which time, the name had changed to Tamar Brickworks and Potteries Limited ??). White firebricks and terracotta tiles were produced and latterly chemical stoneware. Clay came from a pit across the road and was brought in through an adit via a tramway. They used a Hoffman kiln with 16 compartments. All the works have been demolished and the clay pit backfilled. It is now the site of the Cox Park caravan site.

Sandhill Works, Drakewalls
The works was in operation for about twenty years from about 1860 producing white firebricks. It was owned by B. Johns & Co. There were four beehive kilns, two of which remain. One has been bricked up and the other is a garden shed. The clay pit is now a sunken garden.