34 The Phosphates of America. 



the pit goes down, since the bottom and sides of it now consist 

 almost entirely of massive green phosphate. From careful meas- 

 urements in the excavation, the quantity of total material re- 

 moved from this shaft was computed at about 40,000 tons and 

 the proportion of apatite at about twelve per cent, of the mass. 

 The average daily number of men employed in sinking this shaft 

 and dealing with the ore has been as follows : 



Twenty-five miners and strikers with 1 steam drill underground ;. 

 5 men at the surface unloading the cars ; 25 men and boys in the 

 cobbing-house, engine-house and blacksmith's shop ; total, 55 men 

 and boys. The average wages paid to these grouped together 

 has been $1 per capita and per day. 



The average cost of powder and steam and the wear and tear of 

 drills, engines, hoists, tools and other plant we estimate from prac- 

 tical experience at 25 cents per ton of rock removed. 



From these data it is easy for us to compute the cost of the 

 phosphate per ton. 



55 men and boys at $1 per day for 300 days $16,500 



40,000 tons of rock removed at 25 cents per ton for plant 

 and wear and tear. ...*.... 10,000 



Total cost of, say, 5,000 tons clean phosphate.. .$26,500 

 or, say, $5.60 per ton at the mine. 



The width of the pyroxene belt in the neighborhood of this 

 shaft is about 300 feet, and saving that in some places there is a 

 considerable intermixture of huge granitic bowlders, there is no 

 change in its predominating characteristics over the remainder of 

 the property. 



The equipment necessary to the proper working of an apatite 

 mine must include : 



One or two good boilers of about 50 H. P. each. 

 One or two double drill compressors. 

 One or two hoisting engines of about 20 H. P. each. 

 Three or four machine drills fully equipped. 

 All necessary fittings and pipe for compressors. 

 A first-class plunger pump. 

 A first-class double forcing pump. 



A line of transport wagons of about 2 tons each capacity. 

 A line of transport sleighs, for winter, of about 2 tons each capacity. 

 A commodious blacksmith and carpenter shop, well provided with 

 all kinds of tools. 



A cobbing-house fully equipped. 



