Shafts Through Frozen Quicksands.

Shafts Through Frozen Quicksands.

The achievement of sinking a deep shaft through treacherous ground by first freezing the earth has been accomplished at the Chapin iron mine in the upper peninsula of Michigan by the “Poetsch process,” already described in FIRE AND WATER. The contract was to freeze, excavate and kerb up a rectangular shaft fifteen and one-half by sixteen and one-half feet, and about 100 feet deep. This was done by first putting down the freezing pipes, three feet apart, in a circle twentynine feet in diameter, to the depth proposed to be reached by the shaft. The pipes were connected at the top and filled with a solution of brine containing about twenty-five per cent of calcium chloride. The brine was frozen to a point below zero by means of an ice machine, and in forty days a frozen wall of ice. earth and stone was formed ten feet thick. The excavation in the meantime had been going on, and seventy days from the commencement it was completed to the ledge 100 feet down, in spite of some difficulty from the percolation of water near the bottom, which was stopped by freezing. Except for this ingenious method the sinking of the shaft would, it seems, have been practically impossible on account of the great inflow of water. The Poetsch Process Company is now engaged in sinking a still more difficult shaft through quicksands and water in Wyoming. Pa. The shaft will be 130 feet deep, and it would be almost impossible to make it by any other process known to science.

ORANGE, N. J.—”This city,” writes our correspondent, “ was incorporated in i860 and its population numbers nearly 17,000. The following is a list of its officers : Mayor, Geo. H. Hartford ; city clerk. H. Stetson ; treasurer, C. G. Williams ; chairman of finance committee, G. D. McChesney ; city civil engineer, Rufus Mead ; superintendent of water-works, Thos. Dowd ; chief of police, Wm. McChesney ; chief of fire department, J. W. Hodgkenson ; chairmen of fire and water committee, Thos. F. Garrett and Miles A. Hanchert ; street commissioner, Daniel Brennan ; health officer, Charles Buttner ; firm alarm superintendent, the chief engineer. The streets are macadamized and are lighted with 203 electric lights, by the Essex Company. Additional lights are put in as demanded by taxpayers. The system of water works is reservoir and gravity and is owned by the city. There are 200 hydrants and thirty-five miles of mains. Extensions to water-works are made as required. At present we have no sewerage system but one is to be constructed soon. The total bonded debt of the city is $687,000. No improvements of any account are spoken of for fire department just now. Five, six and seven per cent interest is paid on bonds.”

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