THE MINING AND QUARRY INDUSTRY I9II 39 



The Old Bed workings, reached through the Joker and Bonanza 

 shafts, have been enlarged recently by the development of a separate 

 bed underlying the main deposit. This lower ore body spreads over 

 a considerable area as a nearly flat sheet, in strong contrast with 

 the complex overlying body, and has a thickness up to 30 feet. The 

 ore resembles that of the Old Bed proper, but contains a little less 

 apatite. Both the Joker and Bonanza shafts have been connected 

 through to the deposit which furnished last year about one-half of 

 the quantity hoisted from the Old Bed group. The ore body extends 

 for a considerable distance to the north and west, and it is intended 

 to connect the workings with the Miller pit, as a provision for safety 

 and ventilation. 



The Harmony mines have been usually active, the output going 

 to the new No. 3 mill completed in 1910. The products consist of 

 ordinary concentrates with about 64 per cent iron and extra high 

 grade concentrates with 71.4 per cent iron, the latter being used for 

 making electrodes for arc lamps. The tailings from the mill also 

 find application for road and concrete work. A complete description 

 of this mill which contains many advanced features in the magnetic 

 separation of iron ore has been given by H. Comstock,^ Assistant 

 General Manager of Witherbee, Sherman & Co. 



The work in the Barton Hill mines has been mainly of develop- 

 ment character, preparatory to their steady operation. From the 

 new tunnel a raise has been excavated to the old Orchard pit 

 encountering good ore all the way. For the treatment of the 

 future mine output a new mill is in course of construction, the 

 fourth erected by the company. The mill is designed for a capacity 

 of 100 tons crude ore an hour. It is to be an all-steel structure with 

 corrugated iron cover. The crushing department will be equipped 

 with a 24 by 36 inch jaw crusher and two no. 5 Gates g}Tatory 

 crushers from which the product will go to a storage bin of 1200 

 tons capacity. From the storage bin the ore passes to revolving 

 screens making four sizes each of which is delivered to independent 

 separators of the drum and belt types. These make three products, 

 concentrates that go to the shipping bin, tailings to the stock pile, 

 and middlings which are reground by rolls, sized and again sepa- 

 rated. The power for driving the crushers and separators will 

 consist of four motors of 150 h. p. each. 



The Port Henry Iron Ore Co. obtained most of its product from 

 the Clonan shaft in the southern part of the " 2T " ore body, but 



»The Iron Trade Review, Nov. 9, 191 1, p. 825-29. 



