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LECTURES TO SCIENCE TEACHERS. 



to six hundredweight for each burner ; the pyrites contains 

 usually about 48 per cent, of sulphur, and the charge is 



burnt out in twenty-four hours. In order to ignite a fresh 

 kiln, the kiln is heated to redness by ordinary fuel, and 

 .the charge of "stone" thrown in. The following table 



