268 NEW YORK STATE MUSEUM 



the capacity of the plant. The mine holds the record among the 

 New York magnetite mines in the handling of low-grade ore, as 

 its product for some time has run considerably under 30 per cent 

 in iron, requiring nearly 3 tons crude for a ton of 60 per cent con- 

 centrates. Much of the ore treated has come from the floor and 

 roof of the old workings, but there is still available a large area of 

 unworked ground on the northern and southern borders of the 

 exploited territory, enough to assure a supply for many years to 

 come. An increase in the capacity of the plant which now is rated 

 at about 500 tons of crude a day seems justified economically in 

 view of the available tonnage. 



Lyon Mountain. The low-phosphorus concentrates from this 

 group of mines find a ready market at a premium over the usual 

 prices and of late have been in special demand. The Chateaugay 

 Ore & Iron Co. is the operator. Plans are being put into effect to 

 enlarge the production. A new shaft with a hoisting capacity of 

 3000 tons daily has been constructed to take the place of the sev- 

 eral small, inconvenient openings that have been used in the past. 

 The principal addition to the surface plant is the mill, on which 

 construction was started during the current season and which when 

 completed will affect considerable economies, as well as provide for 

 a larger outturn, in comparison with the old plant. 



Benson Mines. A renewal of operations in these extensive 

 deposits is in prospect for the current season. During 1916 only 

 test runs were made, but it was planned to inaugurate a steady 

 campaign during the present year. The milling plant has been 

 rebuilt, with a change in the method from the dry magnetic concen- 

 tration practised elsewhere in the Adirondacks to the wet magnetic 

 system similar to that employed largely by the mines of central 

 Sweden. The ore is very dense and close textured, necessitating 

 finer crushing and more careful handling than the common ores of 

 the eastern Adirondacks. Owing to the presence of considerable 

 sulphur, the concentrates also require a roast, which is further bene- 

 ficial on account of the accompanying agglomeration that takes 

 place. The success of the undertaking will mean a great deal to the 

 iron-mining industry of the State, as the resources in this class of 

 ore are very large. 



Jayville. The mines at this place, 14 miles west of Benson Mines, 

 on the Carthage & Adirondack Railroad, were under examination 

 in 1 91 6, with a view to their reopening. They are based on a group 

 of shoots and lenses of magnetite, some of which yield a merchant- 



