Report of the Committee on leather for bookbinding . Left side of first skin, cleared with dilutesulphuricacid. Notice how the slickerhas stretched this half skin in breadth. Average breaking stress ofwhole skin in lbs. 17 6 73 51 22 43 45 \ 16 28 75 54 63 92 ? 57 57 96 54 65 > 55 « 51 56 57 31 \ 26 52 27 35 58 80 rt-—^—-^->^1 22 35-3 54-6 65-6 60-85 43-33 Breaking Stresses. Left side, cleared. Right side, not cleared. Average breaking stress of this half skin 46-9 Breaking Stresses. Right side of first skin, sponged four times on the grainwith Peroxide of Hydrogen. N
Report of the Committee on leather for bookbinding . Left side of first skin, cleared with dilutesulphuricacid. Notice how the slickerhas stretched this half skin in breadth. Average breaking stress ofwhole skin in lbs. 17 6 73 51 22 43 45 \ 16 28 75 54 63 92 ? 57 57 96 54 65 > 55 « 51 56 57 31 \ 26 52 27 35 58 80 rt-—^—-^->^1 22 35-3 54-6 65-6 60-85 43-33 Breaking Stresses. Left side, cleared. Right side, not cleared. Average breaking stress of this half skin 46-9 Breaking Stresses. Right side of first skin, sponged four times on the grainwith Peroxide of Hydrogen. Notice how the slickerhas stretched this half skin in length. Average in Average for left side of Average for right side ofskin, 46-5 lbs. skin, 75 lbs. Average breaking stress ofthis half skin, 59-6 E 2 REPORT ON would be in preparation for tannage, but which wasdried out in the raw state. It will be noted that thestresses withstood by this skin are much larger thanthose in any other series of experiments, and thattherefore no part of the tanning process increasesthe mechanical strength of the skin. It will beseen from Nos. 2, 3, 4, and 5 that the skin does notimprove in strength as we proceed with its manu-facture. This is perhaps to be expected since in thesimple dried skin the fibres adhere together andmutually support each other, leaving the skin hardand horny, while the main object of tanning is toseparate and isolate the individual fibres, leaving theskin soft and porous and suitable for its uses, butdiminished in tensile strength. Over-tannage ofany sort materially reduces the tenacity and wear ofall sorts of bookbinding leather. Fi
Size: 1971px × 1267px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookidcu, booksubjectbookbinding
