292 University Geological Survey of Kansas. 
screen, K. Small holes are bored in the lower side of the 
short portions of pipe, which are connected to the main water 
pipe, through which the water runs in small streams, and 
thus loosens up and washes through the screen any fine ma- 
terial such as slime and sand, which may be placed in the 
upper part of the launder. After passing through the screen, 
ix, the slime is borne down the launder and escapes through 
the opening in the lower end, through which the vertical 
shaft passes. Passing downward from the launder, it is 
caught in the hollow or cup-shaped casting, F’, from which it 
escapes by the double row of holes at the base; thence onto 
the sloping surface of the top of the drum, and lastly onto 
the table, from which it escapes by the gate, A. 
The method of operating a round (convex) buddle is as 
follows: The material to be treated is fed, being mixed with 
water as described above, and passing downward reaches and 
spreads out over the convex floor or bottom of the buddle. 
In passing from the centrally placed drum, radially outward, 
a certain fixed volume of dilute slime must of necessity pass 
over a constantly increasing surface, which reduces the thick- 
ness of the sheet of water and very materially diminishes 
the velocity. The carrying power of the water current is 
thus reduced and particles of mineral are deposited upon the 
floor of the buddle, which deposition occurs in order of the 
specific gravity of the materials treated, 7. e., galena, blende 
and quartz is the order of deposition. When the buddle has 
filled to the depth of 8 to 12 inches, the feed is stopped and 
the accumulation of mineral and sands is marked off and re- 
moved according to its richness. For instance, the first 4 
inches, next to the drum, may be fairly rich galena; the next 
8 inches, fifty per cent. blende; the next 24 inches, twenty per 
cent. blende; while the remainder is little if any richer than 
the original material fed to the buddle. Each of the succes- 
sive rings of material is removed and, when asufficient amount 
of a certain grade has accumulated, is rerun over the same 
or other buddles of similar make. As a rule, in each mill 
where buddles are operated, certain ones will be run as 
roughers, the product of which is retreated on other buddles, 
often called finishers, which still further concentrate the ma- 
