GOLD MINING m COLORADO. 571 



toward one side or the other, and the upper ends of which are pointed, so as 

 to assist somewhat in the division of the several classes of the material at the 

 place of discharge. 



The lower end of the table is also pierced with slits, or apertures,/ and 

 k, Fig. 2, through which the material may be discharged from the table before 

 reaching the lower edge, falling thus into troughs, or launders, which conduct 

 the different assortments to their appropriate places. The outer one of these 

 launders, /, receives the clean ore from the lower edge of the table ; the second, 

 I', receives the "middlings" through the aperture k ; and the inner, I", receives 

 the waste stuff through the aperture j. 



Another arrangement for the disposition of the assorted material, without 

 the use of apertures, is shown in Fig. 5, in which the poor stuff, or gangue, is 

 discharged over the edge of the table into the launder I"; the other two classes 

 fall into the box 77i, which is divided into two parts, opening in opposite direc- 

 tions, that part which is under the discharging point of the clean ore opening 

 to the right and delivering the stuff into the launder I, the other part receiving 

 the middlings and delivering into the launder 1/ The table is suspended in 

 an upright framework, as shown in the drawing, by iron rods, the length of 

 which may be somewhat increased or diminished, as may be desired, by means 

 of the screw near the point of support. The percussion timber, p, forms a 

 part of the frame of the table. One end of it rests against the timber e e'; 

 being strongly pressed in that direction by the spring, d, which is attached to 

 the other end. Motion is communicated to the percussion timber^, and thus to 

 the table by rods, n, which connect it with a perpendicular rod, o, against which 

 the cams, c, strike. The rods n are attached to p by means of a nut, q, shown in 

 Fig. 6, which moves on a screw, and may be adjusted, for the purpose of 

 shortening or lengthening the stroke by turning the head, r. When the cam, 

 c, presses against the block at o, it moves the table in a lateral direction, com- 

 pressing the spring, d, which latter, as soon as the pressure of the cam is 

 relieved, throws the table back against the timber, e, producing the shock, the 

 force of which is regulated by a screw, s, applied to the middle of the 

 spring and entering the framework above the table. The force of the stroke 



near tlie lower end and is supported above it by resting on the upper edges of the side 

 and partition strips, 7t, to which it is naUed. 



