. Engineering and Contracting . tream, insures its correct position. Our experience leads usto advise that the vertical tube be not used as a reservoir,but only as a support for the pitot orifice. The tube is held in its guides by two clamp screws, and mayreadily be set so as to bring the pitot orifice in the locus ofmean velocity as it may be judged or found. In these experi-ments it was set at 6/10 depth of water, and % the width ofthe channel from either side. A scale of feet and tenths onthe tube, reading up from zero at the pitot orifice, and aidedby another scale or gage painted on the s
. Engineering and Contracting . tream, insures its correct position. Our experience leads usto advise that the vertical tube be not used as a reservoir,but only as a support for the pitot orifice. The tube is held in its guides by two clamp screws, and mayreadily be set so as to bring the pitot orifice in the locus ofmean velocity as it may be judged or found. In these experi-ments it was set at 6/10 depth of water, and % the width ofthe channel from either side. A scale of feet and tenths onthe tube, reading up from zero at the pitot orifice, and aidedby another scale or gage painted on the side of the concreteflume, reading up from zero at the flume bottom, readily per-mitted this. The apparatus is mounted on two beams cross-ing the water channel and at a convenient height above it. This apparatus exists as yet only in theory and should beexperimented with at the first favorable opportunity, becauseon drawing the water out of the flume at the close of our ex-periments a broken and leaky joint was discovered in the. rubber pipe that carried the water pressure from the verticaltube to the hookage pail, so that the readings taken provedunreliable, or of no record value whatever. Need and Scope of Further Experiments.—A crew of sixmen, including three observers, with a captain, had been work-ing with the apparatus from Sept. 10 to Oct. 3, 1919, and itwas with great regret that the writer gave the order to dis-mantle the weir because so much remained to be discovered. But Oct. 3 was Friday, the last day of the week for us. Thelaboratory closed at 5 p. m., and on Monday the regularschool term commenced. The appropriation for the workwas nigh exhausted and it was high time we quitted thepremises. There was, first of all requiring further investigation, theeffect of the radius of the weir crest. Bazin had experimentedon a weir composed of two 2:1 slopes meeting at a sharpangle and with a little pipe to indicate pressure under thenappe, let into the body of the weir slop
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