Collection: Directories and Documents > Pamphlets

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Title: Annual Report of the Brunswick Consolidated Gold Mining Company (PH 16-10)(01-22-1914) Collection Type: Directories and Documents Collection Name: Pamphlets Catalog #: PH 16-10 Author: Brunswick Consolidated Gold Mining Company Published: 01-22-1914 # of Pages: 18 Download PDF: User Login Required Download OCR Text: User Login Required

Metadata By: Shelby Figueroa Printed or handwritten: All printed text Date Scanned: 2024-12-10 14:45:29 Scanned By: Shelby Figueroa Scanning Equipment: CZUR Book Scanner OCR Software Version #: tesseract 5.4.1 Item Sourced From: JPGs First Created: 2025-03-17 05:46:27 Last Updated: 2025-03-17 05:46:27

Original Held At: Searls Historical Library Location: 161 Nevada City Hwy, Nevada City, CA 95959

Page: of 18  

NEW SHAFT. On Jan. ist, 1913, the new vertical shaft had been completed to a depth of 400 feet, and a vertical upraise, of smaller area than the shaft, was coming up from the 1250 foot level to connect with it. This upraise broke through into the bottom of the shaft during the last week in February, making an almost perfect connection. Mr. B. C. Uren of Nevada City made the survey for the location of the upraise, and the skill and accuracy displayed by him in this work, which involved a difficult traverse of more than a mile, is deserving of more than passing notice. The work of following down the upraise, and enlarging and timbering it to the full size of the shaft, was completed late in December, the total depth of the completed shaft being 874 feet. It is proposed to sink at least 250 feet deeper, and this work is now in progress. This shaft is connected with the old incline shaft by a drift on the 1250-foot level nearly half a mile in length. This drift has a heavy grade toward the incline shaft, so that the drainage is in that direction, and the ore above the level has to be trammed that way. Furthermore, on account of the flat trend of the No.4 ore shoot, the stopes above the 1250 level, as they are advanced, are making rapidly to the west, and the ore mined from . them can be best handled through the incline shaft. On the other hand, the ore that will be developed below the 1250 level will be in closer proximity to the new vertical shaft and can be more conveniently handled through it. The conditions are such, that, with both shafts hoisting ore, we will be practically working two mines, and it will probably be found advisable to eventually erect a new mill near the new shaft to work the ore hoisted through it, and to continue working the old mill on ore from the upper levels. MILL. The mill has done remarkably good work during the year. The average gold and silver content of the ore milled was $13.92 per ton. From this was extracted $12.607 per ton, or 90.6% in bullion, and $ .981 per ton, or 7%, in concentrates, making the total extraction $13.588 per ton, or 97.6%. The average value of the tailings run to waste was $ .329 per ton. The ore is crushed in the batteries to pass a No. 0 punched tin screen, equivalent to about 45 mesh wire screen, and, because of this fine crushing, the duty per stamp is only about 2.36 tons per 24-hour day. With a coarser screen, the stamp duty could easily be materially increased, but experience has shown that a much lower extraction would result. Because of the small tonnage treated, the milling costs are relatively high, amounting to $1.071 per ton. This figure, however, includes a charge of 28c per ton for freight and treatment, and loss in treatment of concentrates, and a charge of 4.4c per ton for bullion freight and refining charges. Repair work in the mill included the housing in of the east end of the vanner room with galvanized iron, the installation of two new, suspended Challenge ore feeders, and the enlargement of the bullion melting room. IMPROVEMENTS. The actual sum charged to improvements, including new machinery, during 1913, was $11,514.61, but this does not include new cars, new ore buckets, new air drills, a new safety cross head, and numerous other tools and appliances which were added to the mine equipment and charged to operating accounts. A new electrically driven Ingersol Rand compressor, with a capacity of 1500 cubic feet of air per minute, was installed 5.