276 ISAAC A. HOURWICH 



be well cleaned, for it would otherwise prove refractory in 

 smelting. If there be any lumps of uncommon size, these 

 are beaten smaller. The object is to bring the lumps as near 

 as may be to a uniform size, so that the heat may operate 

 equally in desulphurating the ore. It is desirable that the 

 lumps should be about the bigness of a man's two fists, or 

 about 15 pounds in weight; if too small, a difficulty and a 

 waste is experienced in smelting. In this state the ore is 

 conveyed to the furnace and piled on the logs prepared for 

 its reception. When the charge is put in, which may in a 

 common way be about 5,000 pounds, it is surrounded by 

 logs of wood and covered over at the top and the fire is lit 

 up at the mouth below. A gentle warmth is given at first, 

 which is raised very gradually and kept at this point for about 

 twelve hours to allow the sulphur to dissipate ; the heat is 

 then increased for the purpose of smelting the ore, and in 

 twelve hours more the operation is completed and the lead 

 obtained. Wood is occasionally added as the process goes 

 on, and there is a practical nicety required in keeping the 

 furnace in proper order, regulating the draft of air, etc., so 

 that some smelters are much more expert, and thereby ex- 

 tract a greater quantity of lead from a like body of ore than 

 others. This furnace is called the log furnace, and so far as 

 I know, is peculiar to this country. It is of very simple 

 construction, consisting of an inclined hearth, surrounded 

 by walls on three sides, open at top, and with an arch for 

 the admission of air below, and upon the whole it appears 

 well adapted to the present situation and circumstances 

 of the people. It is cheap, simple, may be built at almost 

 any place, and answers the purpose very well. A good fur- 

 nace of this kind may be built at an expense of from $50 to 

 $60, every expense considered." 



It does not seem from this description that the white 

 miners and smelters had by that time made much improve- 

 ment upon the primitive methods of the Indians. It was 

 not before 1836 that the log furnace was superceded by the 

 blast furnace. 



Ignorance of scientific methods caused the early miners 

 to throw away the lead carbonate, or cerussite, which they 



