194 A TOPOGRAPHICAL 



from 20 pits, they would not be exhausted in 1000 years. One- 

 half of this valuable property belongs to Lord Dudley. 



Plot says, " the clay that surpasses all others is that at Amble- 

 cote, on the banks of the Stour, of a dark bluish colour, whereof 

 they make the best pots for the glass-houses of any in England; 

 and it is so necessary to be had that it is sent to London both by 

 land and water-carriage ; the goodness of which clay, and plenty of 

 coal hereabout, no doubt has drawn the glass-houses into these 

 parts, there being divers set up at Amblecote, Old Swinford, Hol- 

 loway-end, and Cobourn-brook." 



This valuable mineral, or glass-house pot-clay, supposed to be 

 found no where else in the known world, is about 150 feet below 

 the surface., 'and 45 feet below the coal, to the extent of nearly 200 

 acres, but the best sort is only found upon about 48 acres: the stra- 

 tum is about two feet and an half thick, of which the middle is the 

 finest. The outside is carefully picked off, and used in copper 

 mines. The principal proprietors are Lord Foley, who has three 

 acres, Edward Hickman, Esq. twenty-three, and Mr. Waldron, 

 twenty-one : Lord Dudley has also some clay in the neighbourhood. 

 This clay is taken up in lumps of lOOlbs weight each, which are 

 afterwards carefully washed, picked, and scraped by women. One 

 yard is calculated to produce a ton, and 4000 tons a-year are got : 

 it will fetch from 34s. to 44s. per ton. It is sent to most of the 

 manufacturing towns in England, Ireland, and Scotland ; and con- 

 siderable quantities are exported for the use of chymists, and fur- 

 naces requiring very strong fires. The exportation of it as fuller's- 

 earth is prohibited unless manufactured; on which account it is 

 shaped like bricks, which may be ground down and used as clay. 

 It possesses this peculiar excellency, that a pot made of it, with a 

 proper heat, will melt almost any thing into glass, provided it be 

 fluxed with proper salts. The largest pots made of this clay arc 

 for crown glass, plate glass, broad glass and bottles, and hold from 

 15 to near 30 cwt. each ; those for flint glass and phials, from 5 to 

 10 cwt. each. The largest will last one or two months, the smallest 

 from nine to twelve months. 



Broad glass has been manufactured here from the period of its 



first introduction into England from Lorraine and Normandy. The 



art of making glass is very ancient. Pliny* says, glass was first 



discovered by accident in Lydia, by certain merchants making a 



* Natural History, lib. 36. 



