CORRECTIONS FOR MOISTURE IN GAS. 47 



Main, Dean's Primrose and Pearith's WalTs-end. Most of the Companies 

 have the facilities of water-carriage, and purchase their coals at the pit for 

 about 7s. 6d. per ton, and charter a vessel from 8s. to 1 Is. per ton, according 

 to the time of the year. If the gas-works are far from the water-side, and they 

 purchase their coals at the market, the above would fetch from 17s. 6d. to 

 18s. 6d. per ton ; and to a large consumer, for cash, 5s. would be charged for 

 cartage, making a total of 22s. 6d. to 23s. 6d. If the gas-works are at the 



water-side, the charges would be as follows : 



s. d. 



Cost of coal at the pit-mouth, say - 76 



Freight and loading - 8 



Lighterage from ship to wharf - 10 



Gang of men carrying from barge to works, per 



ton, according to distance - 10 



Duty Is. Id., and weighing l^rf. 1 2 



Total *18 6| 



At Birmingham and in the neighbourhood the price for Staffordshire coal 

 is about 8s. 6d. per ton, including all expenses. 



In Scotland the prices, per ton, paid for the different kinds of Parrot coal 

 at the places where they are shipped, are as follows : 



s. d. s. d. 



Lesmahajo 17 



Monkland 16 



Tony Burn 12 



Wemyss - 13 6 



Marquis of Lothian 17 6 



Capledsea 14 



Halbeath 12 



Lochgelly 10 



The price of coke in London varies according to the demand : to retailers 

 who fetch the coke it is now about 16s. per chaldron, to private persons 18s., 

 and if delivered, from 21s., according to the distance. At West Bromwich 

 coke is considered on an average to be worth 4d. per bushel. 



Corrections for Moisture in Gas. 



Gases expand by heat in the proportion of about TS~o~th of their bulk for 

 every degree of Fahrenheit's thermometer between 32 and 212; at a tem- 

 perature of about 1035 Fahr., one volume of gas becomes nearly 2'5*. Dr. 



* Davy, Phil. Trans. 1817, p. 54. 



