CRANE. | Addenda. 367 
treatment of slimes was undertaken at an earlier date, and 
is now more commonly practiced in the Joplin than in the 
Galena portion of the district, although during the last few 
years there has probably been a more rapid development 
along this special line of work in the latter locality. 
Special concentrating mills, commonly known as sludge 
mills, have been designed for the treatment of tailings, sand, 
and slimes, resulting from poorly constructed mills or care- 
less treatment of ores. 
One of the first sludge mills of large capacity was designed, 
built and operated by Emmons & Crowe, who later sold 
out to another company. ‘This mill is still in operation, as 
are several others of similar design. 
The latest sludge mill to begin operations in the Galena 
district is owned and operated by Messrs. Murphy & Friel, 
and is located almost within the city limits of Galena. As 
this mill has most of the slime-treating apparatus common 
to the sludge mills, also several new and important features, 
especially with respect to special apparatus for treating low 
grade and refuse materials obtained from the waste banks of 
the standard concentrating mills, it may be taken as typical 
of the mills operating in the district. Plate XLVI. 
The mill consists of three parts, namely, the power plant, 
the tailings mill, and the slime department. 
THE POWER PLANT. 
The power plant consists of two boilers, an 80 horse-power 
Erie and a 100 horse-power Freeman, which are fed by a 
Snow pump, with suction and discharge of 14 and 14 inches, 
respectively. Directly behind the boilers is the water-supply 
tank for the boilers, which is connected with the city water- 
works. These boilers furnish power for two Erie engines, 
which have 12x18 inch and 11x16 inch cylinders, re- 
spectively, and a small engine (5x7 cylinder) for driving a 
generator. ‘The larger of the Erie engines drives the main 
line shaft in the tailings mill, while the smaller drives the 
machinery in the slime department and a centrifugal pump 
in the tailings mill. | | 
The generator is a No. 1 Triumph Electrical Company 
(Cincinnati, Ohio) make, runs at 1300 revolutions per min- 
