92 GRAVEL AND PLACER MINING IN ALASKA. [bull. 268 
gravel to the surface and conve} T ing to the dump. The face expose( 
b3 T the cross drift at the far end of the runway is worked back towar 
the shaft, and the gravel is trammed in wheelbarrows to the shaft anc 
hoisted. Points 5 feet in length are used to thaw the gravel, and are 
generally used in "batteries" or "crossheads" of four (see fig. IT, 
p. 90). The points are supplied with steam from a orosshead of iron- 
gas pipe, three-fourths inch in diameter, fitted with elbows and short 
pieces of one-half inch pipe leading to the steam hose, to which the 
points are attached. The valves are generally set in these short pieces 
of pipe. The points are driven in with a mallet b} T the point man 
working on the night shift. The points are left in the bank from ten 
to fourteen hours. The thawing is nearly always done on the night 
shift, the onh T men occupied being the point man below and the fireman 
at the boiler above. Each point thaws a block of gravel on an average 
6 feet into the bank, 18 inches on each side of the point and -1 feet high. 
The crosshead is laid on the floor of the drift, at a distance of 10 feet 
away from the face, and the steam hose connecting each cock of the 
crosshead with the individual points must be long enough to reach the 
desired distance for placing the point in the bank. The cross pipe <?, 
to which the hose clamp attaches the hose, should be carried through 
the steel head and brazed on the opposite side so that it will not break 
oft' by a chance blow from the mallet. 
It is considered good practice as a rule to start the points with hot 
water turned through the hose. The points must be driven carefully 
and slowly, and for 10 points distributed along a face the average 
time needed is from one to three hours. The amount of steam 
required for each point has been found to vary in amount from 1 to 2 
boiler horsepower. One and one-half may be taken as a safe average. 
The amount of gravel which a point will thaw appears to vary with 
the length of the point, and this is regulated somewhat by the char- 
acter of the gravel. The 5-foot point has been found the most 
economical size for the small operator. 
A typical illustration of the efficienc}^ of the points in the Fairbanks 
district is the experience at No. 8, below Fairbanks Creek. Points of 
Dawson manufacture, 5 feet long, costing $15 each laid down, were 
used in crossheads of four. They were put in at distances of from 2 
feet 6 inches to 3 feet apart. The points were started with hot water, 
and it took three hours to drive them in. A 12-horsepower boiler 
supplied the steam for 10 points, three-fourths of a cord of wood being 
burned on the night shift, when the thawing was done. In twelve 
hours the 10 points thawed a block of gravel 30 feet in length by 5 
feet in height by 6 feet into the bank— an average of 3.3 cubic yards 
to the point. 
The above is a little high for the average duty in the Fairbanks dis- 
trict, but is low for the Klondike creek drifting operations. A typical 
