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Preservation of chestnuts
176
Adhesion of Flat Driving Belts.
[Jour.Frank. Inst.
in determining the driving power of belts at high speeds. Mr. Grimshaw replied that the conditions of fi'iction were substantially the same, and that conditions varied so that he could not give any reply to any question as to the relative driving power of different kinds of belts at high speeds, without all the conditions being stated. Mr. Sandgran asked if the speaker had made any tests of canvas belts. The latter replied that he had made about 200 under varying conditions with some substance to increase the adhesion, and that its tractive powers under the conditions of' his tests were exceptionally good, while it was the strongest belt that he had ever broken. Mr. Eccles thought that the mode of testing was hardly the right on% the tendency being, by adding weights to both ends of the belt, to break it; and said that he would prefer to attach the dynamometer to the rim of the pulley. Mr. Grimshaw said that the friction between the belt and the pulley was the same as that between the pulley and the belt; that the driving power of any belt was measured by the difference between the tight and the loose sides, and that the pulley got all the difference in the tension; it could go nowhere else. As regards the danger of breaking the belts--the tension possible to put upon any belt was determined by the strength of the lacing or other fastening, and that for lacings the maximum safe strain, as laid down by Briggs & Towne, was 66~ pounds per inch wide; whereas single oak tanned leather belting broke at 1000 pounds per inch of width. Hence the method of testing not only registered correctly both the light and the heavy tension but the difference or grip, and did not induce artificial conditions. It had two certain practical conditions over attaching the dynamometer to the pulley rim.*
Preservation of C h e s t n u t s . - - T h e great consumption of chestnuts in France, both by men and by cattle, renders some contrivance for preserving them a great desideratum, hi. ~fagne has communicated a method to the Agricultural Society, which he has found very successful. He mixes them, in ~ovember, with a dry sanely soil, and places them in a close vessel. When thus treated they can be preserved in good condition until the end of 3Iay or longer.--Zes ~[ondes. C. *Attaching the dynamometer to the pulley rim allows only as much slip as the motion of the spring permits (about ~ inch in the present case); while allowing the belt to slip gives a foot or two.--R. (5.
Adhesion of Flat Driving Belts.
[Jour.Frank. Inst.
in determining the driving power of belts at high speeds. Mr. Grimshaw replied that the conditions of fi'iction were substantially the same, and that conditions varied so that he could not give any reply to any question as to the relative driving power of different kinds of belts at high speeds, without all the conditions being stated. Mr. Sandgran asked if the speaker had made any tests of canvas belts. The latter replied that he had made about 200 under varying conditions with some substance to increase the adhesion, and that its tractive powers under the conditions of' his tests were exceptionally good, while it was the strongest belt that he had ever broken. Mr. Eccles thought that the mode of testing was hardly the right on% the tendency being, by adding weights to both ends of the belt, to break it; and said that he would prefer to attach the dynamometer to the rim of the pulley. Mr. Grimshaw said that the friction between the belt and the pulley was the same as that between the pulley and the belt; that the driving power of any belt was measured by the difference between the tight and the loose sides, and that the pulley got all the difference in the tension; it could go nowhere else. As regards the danger of breaking the belts--the tension possible to put upon any belt was determined by the strength of the lacing or other fastening, and that for lacings the maximum safe strain, as laid down by Briggs & Towne, was 66~ pounds per inch wide; whereas single oak tanned leather belting broke at 1000 pounds per inch of width. Hence the method of testing not only registered correctly both the light and the heavy tension but the difference or grip, and did not induce artificial conditions. It had two certain practical conditions over attaching the dynamometer to the pulley rim.*
Preservation of C h e s t n u t s . - - T h e great consumption of chestnuts in France, both by men and by cattle, renders some contrivance for preserving them a great desideratum, hi. ~fagne has communicated a method to the Agricultural Society, which he has found very successful. He mixes them, in ~ovember, with a dry sanely soil, and places them in a close vessel. When thus treated they can be preserved in good condition until the end of 3Iay or longer.--Zes ~[ondes. C. *Attaching the dynamometer to the pulley rim allows only as much slip as the motion of the spring permits (about ~ inch in the present case); while allowing the belt to slip gives a foot or two.--R. (5.