The Clifton clarion., 1889-05-29

third pair of rolls crushes the mid
 dlings from the coarse jigs finer. MT.
 Colquhoun believes in frequent re-
 working, and, to this end, hsa made
 these alterations in the crushing ap-
 paratus. Hitherto. the mill has been
 simply a jig mill: but it is intended
 to add slime tables. Scales and flakes
 of the oxides, too, complicate the ore
 dressing by the obstinate manner i1
 which they cling to the gangue.
 The work is s;uiplitied iu this dis trict by the fact that the gaDgue is usually light, sulphide of iron absent (iargalv), and iron and limestone de- . sirable to save aa fiuXes. ltis safe to say that 1t were necessary to separate these copper ores from even limestone il could not be done with profit by either of the two mills hereabouts for dress ing these ores. The ores sent 10 the mills are mostly screenings from ore that has to be either sorted or dressed by machinery, hence little of this ma terial is coarse. To relieve the rolls in the Arizona Copper company's mill, Mr. Colquhoun some time ago placed a troemmel under the grizzlies to screen this fine ore. It was quite successful. Another novel idea is q jig in winch Mr. Colquhoun has cn- dCsvored to obtain tbc effect of 3 slow return of the plunger by plac- ing between the plunger compartment and the screen compartment a third compartment. This third tor middie) compartment receives the water or tiinarily supplied to the plunger, a8 its only outlet is below, either toward the plunger or the screen, the down. ward stroke of the plunger acts on the screen without Interruption from the middle, but the suction of the up- stroke is decreased partially by the incoming water and by the air ctish ion.
 An office building constructed of brick moldsd from slag is being erected on oaa of the spurs ofth slag dump near the company's bridge over the San Francisco. The foasdation is certainly substantial, but there are many doubts as to the l: Ouse being so. The brick are run out while still hot because they can then be thrown around roughly without breaking, and they arc built into the wall as soon as cool enough for the nasons to handle them. IL seems as if little time should be allowed to enable the brick to ba proven sound. The bricks are cast iA iron molds by by l2 inches.
 At Morenci the Detroit Copper Mining company rut in ''Bartiett" i furnace, which upon slight alteration has proven quite successful. The al- teration consisted in taking of that part of the arrangement of the bl .st supposed to utilize heat from the pro- ducts of combustion.
 Hot blast" does not meet with favor : iH this section since the Arizona Cop !. per company's expensive experiment proved such signal failure. The con ! nections between the furnace and the !. stove erected ten months ago by the enthusiastic Scotchlnen who selected . Arizona as good field for expert mental stations have been torn out, : and the furnace dismantjed and other . wise abandoned. As, however, the . work was at the expense of the in- ventor's friends, the Arizona Copper company lost little or nothing itselt.- Dr. Alex Trippcl ill the Engineering and Mining Journal.
 Good mining stocks arc low, and . those who buy after carefully diagno- ] sing them cannot fail to make money. ! Col. Ingersoll. with his renowned name !