85

Limited, was formed. A vigorous development campaign was carried
out and some high-grade ore was shipped, but work stopped in August 1924.
Mining was resumed by Duthie Mines, Limited, in July 1925, and in 1926
further shipments of high-grade, hand-sorted ore were made. In 1927 a
modern 50-ton flotation mill (See Plate IV) was built, and 5,500 tons of
ore were treated by the end of the year. A 680-foot crosscut adit was
driven at the mill level to reach the Henderson and Fault Plane lodes.
Development continued on this mill level in 1928 and 14,980 tons of ore
was milled. In the same year Duthie Mines, Limited, became associated
with the Atlas Exploration Company of Ottawa and Mining Issues Corpora-
tion of Toronto. A new boarding-house, bunk-house, and other surface
buildings were constructed in 1929, and extensive mining development was
accomplished. A 600-horsepower, steam driven, electric power plant was
completed and a three-compartment shaft was sunk from the mill (500)
level to the 600 level. Twelve thousand five hundred tons of ore was mined
during the year and 10,370 tons milled. The Hummingbird and Canary
claims were purchased towards the end of the year, giving an additional
2,000 feet along the northeasterly continuation of the Henderson lode for
further exploration. Mining operations were suspended in March 1930,
owing to the depressed metal market. The property is still held by
J. F. Duthie of Seattle.

The following statement of total production from the Duthie mine is
from the Annual Report of the British Columbia Minister of Mines for 1934.

“4788 tons of hand-sorted ore yielding gross smelter returns of
$523,744.92, leaving net smelter returns of $411,705.72, after deducting
freight and treatment rates of $23.40 a ton; 31,956 tons of ore milled
yielded 1,663 tons of lead concentrates and 1,834 tons of zinc concentrates.
Values contained in the tonnage milled were as follows: gold, 776 oz.;
silver, 739,055 0z.; lead, 1,920,487 lb.; zinc, 1,606,014 lb. The following
may be taken to represent the average tenor of the various products:—

Feed: Silver, 37-2 oz. per ton; lead, 4-8 per cent; zinc, 5-2 per cent.

Lead Concentrates: Gold, 0:27 oz. per ton; silver, 430-8 oz. per ton;
lead, 48-6 per cent; zinc, 10-9 per cent.

Zine Concentrates: Gold, 0-093 oz. per ton; silver, 36 oz. per ton;
lead, under 1:4 per cent; zinc, 47-2 per cent. Savings effected, 95 per
cent of silver contents, 95 per cent of lead contents, and 80 per cent of
zine contents ”’.

The principal vein-lodes, known as the Ashman, Henderson, and
Fault Plane, are developed by several miles of underground workings
and have furnished all the ore taken from the mine. There are nine
levels, four of which are adit drifts. From top to bottom they are named
or numbered as follows: Thompson or -10, McPherson or 65, Intermediate
or 145, Compressor or 245, Mill or 500, and sub-levels 265, 300, 400, and
600. The numbers denote the vertical distances below an elevation of
3,840 feet, 10 feet below the Thompson level.

The property is underlain by rhyolite, dacite, and andesite flows and
flow breccias and by rhyolite tuffs (See Figure 9). The mine workings
above the 500 level (600 level was not examined) are in rhyolite flows and
silicified rhyolite tuffs. These rocks are overlain on the east and south