URINGTON.] 
OPEN-CUT MINING. 
61 
% cable 
Many deposits were seen now worked by shoveling into sluices 
vhere at least an experimental trial of this method is to be recom- 
nended. One of the strongest points in its favor is the cheapness of 
nstallation and the mobility of the apparatus used. 
STEAM SCRAPERS. 
In view of the economical showing which the steam scraper has made 
n handling tailings from the creek-mining operations of the Klondike 
t is remarkable that so few at- 
;empts have been made with it 
:o scrape the alluvium from its 
>riginal position. The ordinary 
scrapers used in steam-scraping 
operations on tailings in the 
Klondike have a capacity of from 
>ne-third to one-half cubic yard, 
>perated by double drum, 2-cylin- 
ler hoist; 16-inch drums, 25 to 
\0 horsepower capacity, handling 
>n an average 250 cubic yards 
>f loose material in twenty-four 
tours, at an average expense of 
:9 cents per cubic yard. The 
manipulations of the scraper, con- 
idered as a unit of the plant, take 
I to 4 men on shift — a fireman, a 
[joistman, and either 1 or 2 men to 
ill, guide, and dump the scrap- 
jr. The form and rigging up of 
jpe scraper, with the system of 
heaves, pulling, and drawback 
xibles, is shown in figs. 6 and 7. 
I(i the practice seen the scrapers 
rag the material from the pit to 
lie dump, a distance measured 
prizontally from 100 to 300 feet 
ijid vertically from 20 to 50 feet, 
pe scrapers are not always provided with teeth like the one shown 
i the figure, but this is advisable. A rigid bale should never be 
{|ed, as flat stones catch between it and the body of the scraper. 
'he plants average $3,500 in cost. 
,The rig shown in PI. VI, A (p. 62), is situated on Walker Fork, Forty - 
ijile district, Alaska, where a body of gravel 60 feet in width and 5 
let in depth, with little or no stripping, was being mined. Accord- 
ing to information obtained by Mr. L. M. Prindle the gravel was only 
Fig. 6. — Small steam scraper, Klondike. 
