GOLD MINING IN COLORADO. 569 



satisfactory results that have been generally obtained by the Rittinger table 

 in Europe leads to the opinion that it should be well adapted to the treatment 

 of our ores, in Colorado and elsewhere. It has already been described in one 

 or two works published in this country, but it is deenned of sufficient import- 

 ance to be noticed here, in connection with the subject under consideration. 



The following description of this percussion table is taken from Von Rit- 

 tinger's Lehrbuch der Auf bereitungskunde.^ The drawings on Plate XXXIV, 

 copied from the Atlas accompanying the above-named work, show the details 

 of its construction. Fig. 1 is a front elevation of a double table; Fig. 2 a plan; 

 Fig. 3 a side view; Figs. 4, 5, and 6 show other details, to be noticed further 

 on. This apparatus consists of a wooden table, or platform, about four feet 

 wide and eight feet long, which is suspended by iron rods at the four corners, 

 as shown at h, b, Figs. 1, 2, and 3, presenting an inclined plane, over which the 

 water and material, supplied at the upper end, may flow evenly toward the 

 lower end. The table is so hung as to move freely, in a lateral direction, 

 w^hen acted upon by a cam, c, and may be thrown back by the action of a 

 spring, d, so as to strike forcibly against a timber, e, firmly imbedded in the 

 ground, by which means a shock is imparted to the table and the material 

 upon it. 



The characteristic features of this table, as compared with the ordinary 

 percussion table, already many years in use, are that the shock is applied at 

 one of the long sides instead of at the end, and that it is self-discharging and 

 continuous in its operations. On the old-fashioned percussion table the mate- 

 rial being supplied at the upper end and evenly distributed across the width 

 of the table by a stream of water, and the shock being likewise imparted at 

 the same end, the tendency of the heavier particles is to move backward at 

 each throw, or shock, of the table, while the lighter particles, following the 

 impulse of the stream, move downward toward the front edge and are there 

 discharged. In the case of the Rittinger table all the particles which are fed 



1 Since the above description was written and the accompanying Plate engxaved, 

 the first supplement to Von Rittinger's treatise (Erster Nachtrag zum Lehrbuche der 

 Aufbereitungskunde) has been received. It describes several modifications in the 

 construction and application of the continuous percussion table, for which, in. detail, 

 the reader must be referred to the original source, but the most important of which 

 are noted here. 

 •72 



