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Show Record as to hold the sampler in a vertical position or as nearly as possible in a vertical position. We punch a hole five- eighths of an inch in diameter in the cap on the milk bottle, and cover this cap with a piece of wrapping paper. The bottle is put into the sampler and the sampler is lowered to the desired depth. We start in by taking samples from the bottom of the river, and take some from the middle depth and some at the surface. We hold the bottle at the desired depth, and a second weight, about three- quarters of a pound, would slide down on a wire and push a plunger down. The best samples are obtained by putting the bottles at the bottom of the river, and pulling it up at such a rate that the bottle shall be full just as it gets to the top. In addition to silt samples we would take water samples which were primarily for the determination of the dissolved mineral matter in the water. We have made determination of the quantity of suspended matter in these samples, but because of the place where the water samples were taken, we feel that the percentage of matter in 3797- B these water samples is too low. However, they do serve as a check on the minimum quantity carried by the river. Our silt and water samples, Bright Angel Station, have been collected since 1924. At Topock Station we started at the same time a collection of water and silt samples. At Yuma we took water samples from October, 1927, to September, 1928. Samples have been taken at Lees Ferry from October 1st, 1928, to the present time 3798 The samples at Lees Ferry were taken by the gager and are shipped to us at no particular intervals. He takes the water samples daily. The silt samples he has taken three times a week, except during the period of rapid fluctuation. On the San Juan River, from August 12 to September 21, 1928, I took something like 570 silt samples. This summer on the Sam Juan we had an observer from Washington in addition to the regular observer. Mr. Love took something over 700 samples between the 10th of July and the 21st of |