THE MINING AND QUARRY INDUSTRY I909 47 



plan of ore treatment will conform in general to that practised 

 in the other mills, with such improvements as experience has 

 suggested. The ore will undergo a preliminary crushing at the 

 shaft houses and then be carried to a looo-tone storage bin at the 

 mill. After further reduction it will pass through Ball-Norton 

 drum separators, then wil/l be recrushed to >4-inch size and separated 

 on belt machines. The capacity of 800 tons in 10 hours for 

 which the mill is designed will no doubt be considerably ex- 

 ceeded in practice. The development of the Harmony mines 

 has yielded such favorable results that another mill was needed 

 for handling their output. 



The additional power required for the enlarged operations 

 at Mineville has been provided for by the installation of a new 

 1500 kilowatt turbine engine at the Port Henry station. A low 

 pressure turbine which uses the exhaust from a Corliss engine, 

 has also been installed at the Mineville power house. 



Some interesting developments have occurred in connection 

 with recent explorations, through which additional light has 

 been thrown upon the structure and geology of the ore bodies. 

 The great Joker-Bonanza body has been shown to have quite 

 different outlines on the southern section than had been antici- 

 pated, while another deposit apparently unconnected with it 

 has been found in the footwall. These changes are indicated 

 more definitely in a bulletin^ recently issued by the State 

 Museum. 



A test hole put down in the old workings on Barton hill had 

 reached (March 1910) a depth of about 1000 feet. The rock 

 shown in the core belonged to the ordinary type that forms 

 the walls of the principal ore bodies, with occasional bands of 

 dark hornblendic gneiss. No gabbro was encountered in the 

 section, though that rock occurs on the eastern slope of the 

 hiJil. The ore-bearing gneiss thus continues without a break to a 

 coiisiderable depth below the point reached in the mine workings. 

 Between the depths of 960 and 990 feet the rock was heavily 

 charged with magnetite, but little ore was found. 



Cheever mine. This, the oldest of the iron mines in the Port 

 Henry district, has assumed new life after lying idle for many 

 years. The ownership of the property, formerly held by O. S. 

 Presbrey, who was instrumental in restoring it to activity, has 



1 Kemp & Ruedemann. Geology of the Elizabethtown and Port Henry 

 Quadrangles. N. Y. State Mus. Bui. 138. 19 10. p. 106 et seq. 



