. Report upon the forestry investigations of the U. S. Department of agriculture. 1877-1898. Forests and forestry. Per cent. 8 8 Yard dry. 125 -f- (green). 125 4- (green). Average strength of all pieces. Lbs. per t> 4,900 10,800 6,010 8,300 2,670 4,090 Greatest difference in strength between adjoin ing pieces Lbs. per &q, in. 190 380 480 1,110 130 70. Greatest dif ference m en tire scantling, l. e., 6-10 loot piece. Per cent. 18 10 20 87 20 15 It will be observed that green cypress excelled in its uniformity; that green loblolly proves not more uniform than dry white and longle
. Report upon the forestry investigations of the U. S. Department of agriculture. 1877-1898. Forests and forestry. Per cent. 8 8 Yard dry. 125 -f- (green). 125 4- (green). Average strength of all pieces. Lbs. per t> 4,900 10,800 6,010 8,300 2,670 4,090 Greatest difference in strength between adjoin ing pieces Lbs. per &q, in. 190 380 480 1,110 130 70. Greatest dif ference m en tire scantling, l. e., 6-10 loot piece. Per cent. 18 10 20 87 20 15 It will be observed that green cypress excelled in its uniformity; that green loblolly proves not more uniform than dry white and longleaf pine; that wood of the conifers far excel even the tuliptree (poplar) with its uniform grain and texture; and that oak, as might be expected, is the least uniform. It will'also bo noticed that even in one and the same short scantling (6 to 10 feet) of select quarter-sawed longleaf pine differences of 10 per cent may occur, and that in all others these differences were even greater. Incidentally in this and the following experiment a small number of the blocks were thoroughly oven-dried (to about 2 per cent moisture), and it was found that the strength of both cypress and loblolly was increased by about 150 per cent during drying, so that wood ab 2 per cent is about two and one-half times as strong as perfectly green or soaked material; and also that drying from 8 to 10 per cent to the lowest attainable moisture condition d to 2 per cent) still adds about 25 per cent to the strength of the wood. In the following diagram and table a part of the results are presented in detail: //tOOO{ /QOO& 6,000 7000 6,000 5,000 4,000 3O00 BlOC/f#M£ffc/. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Fernow, B. E. (Bernhard Eduard), 1851-1923; United States. Forest Service. Washington, Govt. print. off.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectforestsandforestry
