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. 1921 edition. Excerpt: ...it also has much greater strength. In one comparison a ditch that was being covered to the thickness of one inch had a depth of four feet and a bottom width of six feet with side slopes of one to one. Seventeen linear feet of this ditch was covered in one hour by the gun, three men being employed in ...
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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. 1921 edition. Excerpt: ...it also has much greater strength. In one comparison a ditch that was being covered to the thickness of one inch had a depth of four feet and a bottom width of six feet with side slopes of one to one. Seventeen linear feet of this ditch was covered in one hour by the gun, three men being employed in its operation. Practically the same amount of material was used as was required by five men to cover the same distance by hand. They applied a coating one and a half inches thick, which is an indication of lower density; and it took the five men two hours and forty minutes. This means a saving of 40 per cent. in the cost of machineplaced mortar as compared with hand-placed mortar. To determine whether there was any appreciable difference in the water-tightness of the two coatings, holes were dug behind the walls to a depth of a foot below the bottom of the ditch. These holes were then filled with clay and water. When the puddle reached the height of three and a half feet above the bottom, the hand-placed mortar broke up from the hydrostatic pressure and the permeation of the moisture. The gun-placed material was able to withstand a height of five feet without any effect other than a % inch rising of the bottom. Samples of gunite, as cement-gun placed mortar is called, have been tested in the laboratories to determine the imperviousness of the mortar, and at the University of California samples one inch thick were subjected for two hours and twenty minutes to a pressure equivalent to that of a column of water 1,610 feet high, with no indication of moisture coming through. At 3,400 feet the specimen broke on bending, after having leaked a little just before breaking. Still another series of tests has been made to determine how effective is the...
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Add this copy of The New Stone Age to cart. $63.11, new condition, Sold by Media Smart rated 4.0 out of 5 stars, ships from Hawthorne, CA, UNITED STATES, published 2019 by Wentworth Press.
Add this copy of The New Stone Age to cart. $68.07, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2019 by Wentworth Press.
