"It is calculated in England that the ordinary Summer run of streams does not exceed ten cubic feet per minute per square mile, and that the average for the whole year, due to springs and ordinary rains, is twenty feet per minute per square mile, exclusive of floods--and assuming no very wet or high mountain districts (Breadmore, p. 34)--which is equal to about four inches over the whole surface. If we add to this the six inches that are supposed to run off in freshets, we have ten inches discharged in the course of the year by the streams. The whole filtration was 11.29 inches--10.39 in the Winter, and .90 in the Summer. The remainder, 1.29 inches, is supposed to be consumed by wells and excessive evaporation from marshes and pools, from which the discharge is obstructed, by animals, and in various other ways. These calculations were made from experiments running through eight years, in which the average fall of water was only 26.61 inches per annum. When the results derived from them are applied to our average fall of 35.28 inches, we have for the water that constitutes the Summer flow of our streams 13.25 cubic feet per minute per mile of the country drained, and for the average annual flow, exclusive of freshets, 26.50 cubic feet per mile per minute. That is to say, of the 35.28 inches of water that fall in the course of the year, 5.30 run away in the streams as the average annual flow, 7.95 run away in the freshets, and 20.47 evaporate from the earth's surface, leaving 1.56 for consumption in various ways. In the whole year the drainage is nearly equal to one cubic foot per second per square mile (.976), no allowance being made for the 1.56 inches which is lost as before stated. These calculations are based upon English experiments. Mr. McAlpine, late State engineer and surveyor, in making his calculations for supplying the city of Albany with water (page 22 of his Report to the Water Commissioners), takes 45 per cent of the fall as available for the use of the city. Mr. Henry Tracy, in his Report to the Canal Board of 1849 (page 17), gives the results of the investigations in the valleys of Madison Brook, in Madison County, and of Long Pond, near Boston, Mass., as follows: