28o ISAAC A. HOURWICH 



is so strong as to interfere with mining. The miners lease 

 one or more lots from the lessee of the tract, and begin opera- 

 tion by sinking a shaft. 



'The zinc ore, or jack, is purchased at the mines by jack 

 buyers representing American and European smelters. These 

 buyers bid on the week's output of zinc ore. They make 

 an offer of so much a ton for all of the ore to be taken 

 out of the mine during the week. If the offer is accepted, 

 the jack buyer sends his wagons to the mines, and hauls the 

 ore to the cars for shipment to the smelters for which he buys. 

 Every Saturday evening is settling up time. Then the mine 

 owners, miners, and ore buyers assemble in the various towns 

 in the district, and the ore buyer draws a check for the ore 

 purchased from each mine. The check is made payable to 

 the landowner upon whose property the ore was mined. He 

 takes out his 10 per cent royalty, and passes the balance to 

 the original lease holder, who takes out his 10 per cent royalty 

 and gives the balance to the mine operator, who pays his 

 operating expenses out of the share he receives." 



The larger companies which have their own smelters 

 buy all the ore from their lessees at a stipulated price, de- 

 ducting from the same their royalties. 



It is of great theoretical and practical interest to note 

 the special conditions which have permitted of the survival 

 of zinc lead mining on a small scale, and often with primi- 

 tive methods, amid concentration of ownership in mineral 

 lands. 



The subject is treated from a technical point of view 

 in the twenty second annual report of the United States 

 geological survey, from which the following is quoted: 



'The individual ore bodies are rarely large. The mines 

 must accordingly be shortlived, and the plants must be built 

 to meet that condition. In a district where it is cheaper 

 to sink a new shaft than to tram ore 600 or 700 feet under- 

 ground, central shafts of large capacity are out of place. 

 Large central mills to which the ore of a whole tract is brought 

 are not considered a good investment. In hauling 100 tons 

 of 10 per cent ore 90 tons of waste drift are moved, and when 

 simple and effective mills of small capacity are so easily and 



