A HISTORY OF CORNWALL 



For the purpose of raising the china clay to 

 the surface and preparing it for export, the fol- 

 lowing method is generally adopted, allowance 

 being made for such modifications as the nature 

 of the locality and economical working require. 

 A shaft having been sunk to the required depth 

 alongside the deposit, a level is then driven under- 

 neath the clay which is to be raised. From the 

 level thus made another shaft or ' rise ' is carried, 

 through the clay, to the surface. The over- 

 burden of earth and foreign matter having been 

 removed, a square wooden pipe or ' launder ' is 

 inserted in the c rise ' which is then filled up with 

 clay. This 'launder' is furnished at intervals 

 with holes which, until occasion requires, are kept 

 closed. Arrangements having been made for the 

 supply of a small but continuous stream of water 

 to the clay bed, the surface of the clay bed is 

 now broken up with picks so as to enable the 

 clay to mix readily with the water. The water, 

 holding the clay in suspension, is then carried 

 down the ' launder ' and along the level to the 

 shaft, whence it is pumped to the surface. The 

 milk-white liquid is next conveyed by a series of 

 channels to the clay pit, the channels being so 

 arranged, and the rate of flow so regulated by 

 hatches, as to ensure the deposition of all the 

 heavier particles of sand and mica on the way. 

 In the clay pit the clay is allowed to settle and 

 the water is drawn off, to be used over again for 

 the same purpose. From the pit the clay is 

 ' landed ' into an adjacent tank by the removal 

 of a plug near the bottom of the pit. While in 

 the tank the surface water is drawn off from 

 time to time until the clay assumes the consis- 

 tency of thick cream. From the tank the clay is 

 conveyed to the kiln, where it is cut up into 

 squares, and the remaining moisture driven off by 

 the application of artificial heat. It is now ready 

 for transit. 



The uses of china clay are various. It has 

 been stated, on good authority, that probably not 

 more than one-third of the clay now produced is 

 used in the manufacture of porcelain. In the 

 sizing of cotton goods and in paper-making for 

 the purpose of adding weight and consistency ; 

 and in the manufacture of alum, ultramarine, 

 crayons, water colours, and other similar pro- 

 ducts, vast quantities of china clay are required, 

 both at home and abroad. Besides supplying the 

 home markets, the chief of which are the Staf- 



fordshire Potteries and Lancashire, there is a con- 

 siderable export to the United States, Holland, 

 Belgium, Italy, Spain, France, Germany, and 

 Austria. 



A good clay-bed will produce from I to 2^ 

 tons of clay to every cubic fathom. The 

 selling price of china clay per ton is from I y. to 

 25*. ; but the larger amount consists of medium 

 clays. The official estimate of the value of the 

 output for the year 1904 was evidently calcu- 

 lated upon a much lower selling price, for the 

 purpose, doubtless, of including inferior products, 

 mica-clay, etc. Even so, considerably over 

 320,000 was realized by the merchants in that 

 year, and there are at present no signs of a 

 decline. 



China Stone is granitic rock consisting of 

 quartz, decomposed felspar, and white mica. It 

 occurs chiefly in the parishes of St. Austell, St. 

 Denys, and St. Stephen in Brannel, and has 

 long been used in these and in the neighbouring 

 parishes for building purposes. The towers of 

 Probus and St. Stephen's churches are built of 

 china stone. In 1817 the amount shipped for 

 the manufacture of pottery exceeded that of 

 china clay ; but of recent years, although the 

 output has steadily increased, it has formed less 

 than one-eighth of the whole. Its price varies, 

 according to the quality of the stone, from 8*. 

 to 12s. per ton. China stone is obtained by 

 quarrying, and before being used, requires to be 

 finely ground. The grinding is sometimes per- 

 formed in Cornwall, but usually it is done at the 

 potteries, where also an addition of felspar and 

 other ingredients is made to meet the require- 

 ments of the particular ware it is sought to 

 manufacture. 1 



1 A carefully written and exhaustive account of the 

 ' Hensbarrow Granite District ' by J. H. Collins, 

 F.G.S., appeared in 1878. To this and to the 

 mineral statistics published by the Home Department, 

 and also to Mr. F. N. Olver of St. Just for advice, 

 the present writer is chiefly indebted for the fore- 

 going sketch. Much interesting matter may be 

 found in ' A Treatise on China Clay,' by David 

 Cock. The chapter devoted to this industry by 

 Mr. Brenton Symons, F.C.S., in his ' Geology of 

 Cornwall,' is for the most part a verbatim reprint 

 of the account given by Mr. Collins, to whose 

 work the reader is referred for a fuller treatment 

 of the subject. 



HORTICULTURE 



The warm and equable climate rather than steps which have led to its present importance, 



the nature of the soil of the south-western por- The home of the industry is Tresco, one of the 



tion of Cornwall and of the isles of Scilly has islands of Scilly, and its parent and prototype, 



within recent years led to the extensive culti- the narcissus. Various theories have been pro- 



vation of flowers for the London and other pounded to account for the presence, from time 



markets. Inasmuch as this particular industry immemorial, of some half-dozen varieties of this 



has grown up within living memory, it be- flower, chiefly at Holy Vale and at Tresco. 



comes necessary to indicate briefly the successive Whether these were introduced by some mem- 



578 



