J. Wharton on the Manufacture of Spelter. 169 
single 1 ae furnace of about 45 retorts, upon the Belgian 
only conveniently accessible and cheap American materials 
should be used, the fuel employed was exclusively Pennsyl- 
Vania anthracite, the retorts and condensers were made by our- 
selves, mainly from the fire clay of Perth Amboy, New Jersey, 
and the ore was hydrous silicate of zine, from the Lehigh Zinc 
Co.’s mine near Friedensville, four miles south from Bethlehem, 
Pennsylvania. 
results of the last three of those periods, and show the expen- 
The price of ore was here assumed at rather more than the 
Cost of mining and hauling to the furnace; the price of coal 
Was that actually paid for the small sizes employed, then rela- 
tively less valued than now ; the wages were of course high, 
Pecause but a single furnace was operated, and we were learn- 
4304 Ibs. raw zinc ore at $2.50 per 2,240 Ibs.,------------ $ 4.80 
7,813 Ibs. anthracite coal be $1.75 per 2,240 Ibs.,---------- 6.11 
ages, including manufacture of retorts, &c.,------------ sated 
Clay, &e., and the preparation thereof,------------------ 1.75 
Repairs of furnace and tools,....-.--------------------~ 6.00 
a re ee ae 1.00 
~ Rent ao eerie 60 
ee ee 
nt of buildings, 
(Superintendance, office expenses, &c., not counted), 
