Iron Mining in Minnesota

Iron Mining in Minnesota

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 edition. Excerpt: the old shaft lowered 4 inches. December 7. Last shaft measurement was 105 feet. Ten feet of water in the shaft since Thursday night when a patch on one of the boilers leaked and the fires had to be drawn, only two boilers being left in commission. These will just hold the water at the pumps. Expect to complete repairs by Wednesday. Water in the old shaft lowered 22 inches. December 14. Progress, 1 foot. Patch on boiler repaired in time for Thursday morning shift. To-day a new boiler was set up to run a Prescott Duplex Sinker placed in the old shaft. It is hoped that this will relieve the new shaft. Water lowered 3/2 inches. December 21. Progress, 2 feet. One set of timbers put in. Some low grade soft ore in the northwest corner at a depth of 108 feet. The pumps have reached their suction limit. Five pumps must be lowered next week. Pump was started in the old shaft Monday at noon and beat down the water 15 feet. Surface water measured in the test-pits in the old tunnel was lowered 1 foot this week. Water in the main shaft decreased 700 gallons. Now pumping 2,700 gallons. December 28. Lowered pumps 9 feet. Still have 3 pumps to lower. Holidays interfering with progress. Test-pits show water lowered 10 inches. Water level is now 6 feet 4 inches below the lake level. January 4, 1908. Much time spent in repairing and lowering pumps. Three pumps now in their new position. Test-pit level lowered 1 inch. January 11. On Thursday all the pumps were in place. To get the suction on the upper pumps it was necessary to run the suction through the dividers into the adjoining compartment and carefully pass it between a lot of steam pipes. This took time. Meanwhile two of the bottom pumps gave out and the water immediately rose to the level of the...
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Product details

  • Paperback | 72 pages
  • 189 x 246 x 4mm | 145g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236570804
  • 9781236570802