Assuming that not more than 2,000 acres of the irrigated land at Monterrey were available for sewage purposes, this area would represent the sewage treatment of the present population of not more than 45 persons per acre, and on the basis of the design, that is, for a population of 200,000 persons, this represents not more than 100 persons per acre. In many sewage farms on the continent of Europe, the number treated per acre varies between 80 and 200 persons; for example, at Breslau it is 187, at Berlin 105, at Brunswick 88, and at Steglitz 185. Regarding the crops to be grown on the land, very satisfactory results were obtained from growing Indian corn, and two excellent crops per annum were taken from an area of 500 acres during the period in which the writer was responsible for the works. It was also his intention to grow alfalfa, and turn a part of the land into a pecan grove, and, although he does not share the apprehensions of danger of either Mr. Pitkethly or Mr. Hammond as to growing root crops, he believes the growth of alfalfa, Indian corn, oats, barley, and pecan and fruit trees is eminently suitable for the land, which is a deep rich loam, from 4 to 8 ft. deep, overlying the "sillar" formation referred to in the paper. The writer has seen many sewage farms during the last 18 years, upon which root crops of excellent quality have been grown, and not the least suspicion has ever been raised regarding their use. In reference to the adoption of the monolithic form for constructing the South Reservoir, the writer is so convinced as to its economy that had he to build this reservoir again, he would adopt the same method. Mr. Binckley, in drawing attention to the method of construction, has overlooked the fact that the cost of forms for a reservoir 30 ft. deep was a very serious item, and warranted the adoption of this new method, not only on account of economy but because of rapidity of construction; while, in the case of the Obispado Reservoir, which is very much shallower, simpler forms could be and were adopted. Mr. Saucedo's remarks regarding the repetition of the extraordinary floods of August, 1909, in September, 1910, are particularly interesting, and show how abnormal conditions are in so dry a section of Mexico as the State of Nuevo Leon. These two floods, the writer believes, are among the most instructive in North America, particularly when one remembers that prior to 1909 the average rainfall during a period of 15 years, was less than 22 in. per annum. TABLE 18.--COMPARISON OF VOLUME OF FLOODS, ETC.