| OCR Text |
Show 5822 270 day's work would be, for instance, in a medium stage of water, three periods of sampling: One about 7 to 8 o'clock in the morning; another just before or just after noon, and the third sometime later in the afternoon. At each of those periods, I took samples in the cross- section of the river, either from the highway bridge, in low stages of water, or from the cable from which discharge measurements were made, in high stages of water. I took usually about ten to 12 or 13 samples a day. Q After you took these samples, what did you do with them? A I took these samples in pint milk bottles, similar to the method which Mr. Howard described. I took them to the tent where I stayed, and filtered them through large filter papers. In the first place, I had a definite weight of the bottle; I filtered it; I weighed the filter paper; after filtering, I dried this filter paper in the sun, until it was uniformly dry, and weighed it again; thus I had the weight of the filter paper before and after the sample was taken. I neglected to state that I also weighed the bottle of sample material after taking a sample before filtration; thus I had also the weight of the total amount of material contained in that bottle; and by a simple calculation I could calculate the |
