Читать книгу Tri-nitro-glycerine, as Applied in the Hoosac Tunnel, Submarine Blasting, etc., etc., etc онлайн

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I enclose his reply, and approve his suggestions, subject to your instructions.

I am very truly yours,

W. P. Granger, Engineer in charge.

The Commissioners for the year 1868, report as follows:

During the Summer, Glycerin of a very good quality has been manufactured at this point, under the direction of Mr. Mowbray, and has been used for several months in blasting in the tunnel east of the West Shaft. No accident has attended its use. And while its effect in the heading did not meet the expectations of the Commissioners, the result of its operation in the bench below the heading, justifies the belief that with due provision for its economic use, and essential care and attention paid upon its management, it will prove an effective agent in the prosecution of this enterprise.

The Superintending Engineer, Benj. D. Frost, Esq., reports as follows: “The following is a statement of monthly progress.

Length driven. Total distance from W. Shaft. In November, 1867, 33 feet, 1272 feet. December, 1867, 22 feet, 1294 feet. January, 1868, 33 feet, 1327 feet. February, 1868, 35 feet, 1362 feet. March, 1868, 34 feet, 1396 feet. April, 1868, 24 feet, 1420 feet. May, 1868, 26 feet, 1446 feet. June, 1868, [3] 21 feet, 1467 feet. July, 1868, (Nitro-Glycerin used) 47 feet, 1514 feet. August, 1868, “ 44 feet, 1558 feet. September, 1868, “[4] 51 feet, 1609 feet.

“But for the improved methods of working introduced, the advance would have been much less satisfactory than that we are enabled to exhibit above.