. Proceedings of the annual convention . he needledoes not sink visibly into the mass. In the first place, in connection with this apparatus, we havehere a perfectly smooth piece of plate glass. This needle goesdown and actually touches the glass at the time the index is atzero. The rubber ring is filled with the cement paste and isslipped onto the glass plate. The needle is lowered graduallyuntil it just touches the cement, and then it is released, and thisweight commences slowly to go down through the cement. Asthe cement hardens inside and all over, the gradual hardening FOURTH ANNUAL CONVE
. Proceedings of the annual convention . he needledoes not sink visibly into the mass. In the first place, in connection with this apparatus, we havehere a perfectly smooth piece of plate glass. This needle goesdown and actually touches the glass at the time the index is atzero. The rubber ring is filled with the cement paste and isslipped onto the glass plate. The needle is lowered graduallyuntil it just touches the cement, and then it is released, and thisweight commences slowly to go down through the cement. Asthe cement hardens inside and all over, the gradual hardening FOURTH ANNUAL CONVENTION. 407 and gradual increasing of friction upon the needle should bringit to rest inch before it reaches the glass plate. If it bringsit to rest before that, the cement is setting too quickly; if itallows it to go further before the specified time, the cement isnot setting fast enough. It appears to the Committee that it is athoroughly logical method of testing and one which could beadopted with benefit in our methods of YICAT NEEDLE. Prof. Pence:—I would ask Mr. Condron whether his tests,where he had the wide variations, were made with the ordinaryGilmore needle? Mr. Condron:—They were made with the ordinary Gilmoreneedle. The President:—I ask the Committee if this Vicat needlecan be generally obtained in various places in this country? Isit an article of merchandise? Mr. Kelley:—I would answer by saying yes. I went to theoffice of Fairbanks, Morse & Co. and said I wished the Vicatapparatus, to use in the presentation of the report of this Com- 408 PROCEEDINGS OF THE mittee before the Association. They took this apparatus fromamong- their samples. This particular machine is manufacturedin Philadelphia, and is a regular article of manufacture. Theprice is somewhere between $25 and $30 for the entire outfit. Mr. F. W. Ranno (Southern Indiana) :—How long afterthe cement is mixed before the needle test is applied? Mr. Kelley:—As soon as the cement is m
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