The part of the mountain which holds the coal seams is a high spur which puts off at right angles northward from the crest or backbone, and continues to Lake Washington, a distance of five miles. At the point where the spur leaves the backbone, it may be 1,000 or 1,200 feet high, and it declines gradually to the lake, and then makes a bluff shore-line. On the east side of the spur on Squak Creek it is steep, whilst on the west side, next Newcastle, it drops off more gradually. This difference of grade occasions a great difference in the economy of mining on the two sides.Peculiar advantages for mining possessed by the Gilman Mines. On the east, or Squak Creek side, the ends of the seams are boldly presented, showing in diagonal parallel lines extending from the top of the spur to the creek level, an average exposure of, say, 900 feet in elevation. Here the entries are being driven in horizontally near the water level, and the future progress of the mining will be inward and upward instead of downward and sidewise, as at Newcastle. The entries will all be on the horizontal line crossing the seams. The extreme distance, 1,300 feet. The length of the seams on the company's land is about two miles. Depth below water level, indefinite.
No shipments have yet been made from Squak Creek, Raging River, or Snoqualmie Mountain, but active developing work has been in progress since September last at the Gilman Mines (forty miles from Seattle), and shipping will begin shortly. A switch of only 600 yards in length is required from the main line of railway to reach the outcrop of the coal, and there is every natural advantage for mining.
Seattle Coal and Iron Company.The Seattle Coal and Iron Company own this property, which consists of 1,300 acres underlaid by seven coal seams, five of which will be mined ultimately, three in the beginning. I was able to examine three seams which will Seven seams.be mined at first, and give the following details.
Details.Top Seam, No. 4, descending:
| Roof, rich Bituminous Black Slate, containing streaks of–– | |||
| FT. | INS. | ||
| Coal | 2 | 3 | |
| Bone | 0 | 1½ | |
| Coal | 0 | 7 | |
| Slate, variable | 0 | 0½ | |
| Coal | 0 | 11 | |
| Clay | 0 | 0½ | |
| Coal | 2 | 0 | |
| Clay, variable | 0 | 1¾ | |
| Coal | 1 | 1 | |
| Clay, mining | 0 | ||
| Coal | 1 | 1 | |
| Total, good | 6 ft. 3¼ ins. | ||
Good coal.This is a good seam of coal, five feet six inches of which can be depended on for shipping. The coal is dull-black in color, and easily mined. The bottom is soft sandstone. Overlying the roof-slate, is sandstone. The seam here is said to be one foot thicker than it is at Newcastle.
COAL-BUNKERS OF THE SEATTLE, LAKE SHORE AND EASTERN RAILWAY, ON SEATTLE HARBOR.
Another good coal seam.Seam No. 2 has been uncovered by the diggings on the railroad, and happens to be at an unfortunate place for showing the coal. A stump, partly silicified, with part of its bark lignified, had been taken out of the coal bed, and on each side of it was a tapering band of "Nigger-head," tapering from eight inches at the stump to nothing at the distance of five feet six inches from the stump. Selecting an average place, I got the following section, descending: