EXPLANATION OF PLATES. XVII 



PLATE XXV (Page 190). 



MERCURY. 



Mercury mininff. —Labor or working space on l,50U-foot level, Randol shaft, of the 

 New Almadeu quicksilver mines, New Almaden, Santa Clara County, California. 



At the top, on the left, is a carpenter fitting timber; below him is a pileof broken ore. 

 In the center background are two men drilling a hole for a blast. Facing them is the 

 solid ore. At the right timbers to support the roof may be seen. 



(Cat. No. 516.19, U. S. N. M. From a photograph taken by magnesium light.) 



PLATE XXVI (Page 190). 



JIERCCRY. 



Mercury mining. — Buena Vista shaft and Randol plauilla, New Almaden mines, 

 Santa Clara County, California. 



At the left is the shaft house, and diagonally across the picture is the planilla where 

 the ores are assorted and dressed for smelting. 



(Cat. No. 51661, U. S. N. M. From photograph. ) 



PLATE XXVII (Page 192). 



Mercury smelting. — General view of the reduction works of the New Almaden quick- 

 silver mines. New Almadeu, Santa Clara County, California. 



At the left, in the background, are furnaces Nos. 1 and 2; in front of these is the 

 track for bringing in the ore, and in front of these are the ore houses. In the mid- 

 dle background are several furnaces with their elaborate condensing apparatus. The 

 single-slope roof, on the right, covers the ore bins. Ou the extreme right is a large flue 

 running up the side of the hill to the chimney. In the middle foreground is the works 

 oflBce. connected with it are storehouses and sheds. 



(Cat. No. 51 660, U. 3. N. M. From photograph. ) 



PLATE XXVIII (Page 192). 



MERCURY. 



Mercury smelting. — Reducing furnance No. 1, at New Almadeu mines, New Almaden, 

 Santa Clara County, California. 



At the right of the building is the elevator which takes the ores to a floor above 

 the furnace, where they are distributed V)y cars running on tracks. The square brick 

 furnace is near the center of the building. The heating arrangements are obscured by 

 the load of wood. 



(Cat. No. 51662, U. S. N. M. From photograph.) 



PLATE XXIX (Page 226). 



COAL. 



Coal breaker.— The breaker at the Eliangowan colliery, Shenandoah. Schuylkill 

 County, Pennsylvania. The loaded cars enter on the left, and the coal, after breaking, 

 descends the ctiute and is run into the cars below. 



(Cat. No. 59143, U. S. N. M. From photograph.) 



