December i6, 1892.] 



SCIENCE. 



347 



in that time when the vivifying touch of water shall have reached 

 them. Even now in California, Arizona, Utah, Colorado, and 

 other western States, the subject of irrigation is a dominant one ; 

 and, as it is so vitally concerned with the growth and prosperity 

 of the people, the general government has taken hold of it in cer- 

 tain ways. The titles which head this article are some of the 

 more recent publications concerning this great question. They 

 are by no means all that have appeared, but from a mere glance 

 at them one may glean an idea of the extent and importance of 

 the work. 



The portion of the Eleventh Annual Report of the U. S. Geo- 

 logical Survey, which deals with irrigation, is a comprehensive 

 document, full of valuable information. It is enriched by three 

 maps of the arid region of the United States, and upon which are 

 plotted the areas under irrigation, the forestal areas, and the 

 drainage areas. It may be well to say that the arid region, as 

 defined by the report, is all the country lying between the 100th 

 meridian on the east, and the irregular line formed by the Sierra 

 Nevada mountains, as far south as the 37th parallel and the Pacific 

 Ocean south of it, on the west. Over this vast area there are scat- 

 tered tracts of greater or less extent that are now being irrigated. 

 Tracts that without water would never be able to support any 

 but a scanty population ; but that with it, will be and are the 

 homes of thousands. 



The report details the scope of the work undertaken, and de- 

 scribes the methods by which it was carried on. The means of 

 measuring the volume of water discharged by different streams, 

 the measurements of rainfall, the amount of evaporation from 

 river or lake surfaces, and finally the hydrography of the drainage 

 basins, are all treated in full. The latter is especially complete, 

 for we have here accounts of the Yellowstone, the Missouri, the 

 Arkansas, the Rio Grande, the Gila, the Truckie, the Carson, the 

 Salt Lake, and the Snake River basins. There are also tables of 

 monthly discharges of many large and small streams, and tables 

 of gaugings at various stations. Under the head of ' ' Engineer- 

 ing" are given details of the work of various field-parties. Then 

 comes a statement of the director of the survey, to a House com- 

 mittee on irrigation, in regard to the arid lands. In the course of 

 this the situation and extent of forests, the general physiogra- 

 phy of the district, artesian irrigation, conditions affecting the 

 artesian water-supply, the limit of utilization of artesian water 

 are discussed ; many tables of statistics concerning wells are given, 

 followed by a general consideration of the geological conditions 

 affecting the supply. The last paper is a bibliography of irriga- 

 tion literature, embracing many titles, but not claiming to be in 

 any way complete. This, in brief, is an outline of the contents 

 of the second annual report of the irrigation survey, during the 

 course of which over $235,000 was expended. 



The second title mentioned contains mainly tables of tempera- 

 ture and rainfall for Arizona, New Mexico, Utah, Nevada, Cali- 

 fornia, and Colorado. It is prefaced by a report on the climatol- 

 ogy of the arid region by General Greely, in which are discussed 

 the general features of rainfall over the area. In several appen- 

 dices by LJeut. W. A. Glassford are given accounts of the climatic 

 conditions of the States and Territories dealt with in the report, 

 which will prove of value to the inhabitants of the respective 

 regions. It is not possible to refer in detail to all the interesting 

 features of these reports. We cannot forbear quoting the intro- 

 ductory paragraph to the account of California and Nevada, as it 

 shows the value already attached to irrigation in places where 

 it has been used. It may be well to say, however, that these 

 remarks do not apply to all parts of the State, inasmuch as the 

 rainfall in the north-western portion is normally as great as in 

 many parts of the country where irrigation is never practised. 

 Lieutenant Glassford says : — 



"Irrigation does not present itself to the Calif ornian farmer and 

 capitalist as a mere experiment, as a problem whose solution de- 

 naands the risk of any loss of time or labor, as a thing to be cau- 

 tiously considered and timorously adventured. Here is a State in 

 which all are agreed that the irrigating ditch is the life of the valley, 

 and the only point which at all needs determination is the amount 

 of water available. Here has developed an agricultural population 

 who look upon rainless skies not as a curse, but as the best gift of 



nature, since they have themselves a control over the weather be- 

 yond the reach of men elsewhere. In 40 years the flume of the 

 miner has grown into the ditch of the farmer, and brings to light 

 more wealth now than when its stream was directed upon the 

 auriferous gravels. In these 40 years irrigation has extended 

 until It may now be clearly seen to approximate ihat condition in 

 which all the water available is put to use upon the soil, and no 

 more can be obtained. The limit is in sight even though it has 

 not quite been reached, the limit of water which may be drawn 

 from streams by gravity ditches. The future must deal with 

 other sources of supply and other means of utilizing existing 

 sources." 



The third title, the final report of the irrigation commission or 

 the " Artesian and Underflow Investigations " of the Department 

 of Agriculture, is of a miscellaneous character, but contains much 

 valuable information. A very limited edition only was printed, 

 and it is probably not to be found in many other than public 

 libraries and those of congressmen. The first part, by R. J. Hinton. 

 special agent, deals with the subject in a general way, consider- 

 ing the progress made in America in irrigation works as compared 

 with other countries, its value for fruit culture, and the progress 

 of irrigation in the States and Territories of the great plains 

 region and the Pacific slope. Part 2, by E. S. Nettleton, consists 

 mainly of profiles and maps, but also contains remarks upon un- 

 derground and artesian water-supply of the eastern portion of the 

 plains, largely in the two Dakotas. Part 3, probably the most 

 important of all, contains the reports of the geologists. The ob- 

 ject of this division of the investigation was to ascertain "the 

 source, volume, and availability of the underground waters of 

 most of the area of the great plains." Professor Hay's field was 

 between the 97th meridian and Ihe Rocky Mountain foot-hills. 

 He explains the geological structure, topography, and water-sup- 

 ply of the region, and then devotes considerable attention to the 

 artesian wells of the Dakotas, examining into and describing the 

 geological structure of the country where wells are now found or 

 where they may be successfully sunk in the future. The portion of 

 territory covered by the report of Professor R. T. Hill is in Texas, 

 eastern New Mexico, and Indian Territory west of the 97th 

 meridian. In his general discussion of underground waters, he 

 shows their existence to be dependent upon geological structure, 

 and explains in a lucid way why this is so. Topography, has, of 

 course, much to do with it, but topography is really dependent 

 upon geological structure. There is little likelihood of obtaining 

 artesian water in mountain regions, because of the highly meta- 

 morphosed condition of the rocks, and the (generally) great incli- 

 nation of the strata. On the contrary, he says, " the most favora- 

 ble and usual condition for artesian wells is that of strata inclined 

 slightly at an almost imperceptible angle with the surface slope. 

 This condition prevails in gently sloping basins and not in moun- 

 tains." It is by bearing this principle in mind that successful 

 search for artesian water may be conducted, although, of course, 

 aU gently sloping plains are not equally likely to retain surface 

 water to give it out eventually as artesian. 



Many details of geological structure of the different regions in- 

 vestigated by Professor Hill are given. They are too numerous 

 to be mentioned here. The author's familiarity with the Texas 

 and Indian Territory country enables him to present its geological 

 features with great clearness. This is especially the case with 

 the Grand Prairie regiou. The water conditions here consist of 

 (1) rivers, (2) springs, (3) artesian wells. Of these the most inter- 

 esting and remarkable are the springs. One of the largest groups 

 is a few miles from the city of San Antonio. It forms the head 

 of the San Antonio River, and flows at a rate of 23,000 gallons 

 per minute, or 50,000,000 gallons per day, forming a lake or 

 natural reservoir near the city, and furnishing the 48,000 inhabi- 

 tants with water without any appreciable decrease in the flow of 

 the river. Another group is near Del Rio, on the edge of the Ed- 

 ward's Plateau, about five miles from the Rio Grande. Of this 

 Professor Hill says: "From the deep-seated rock at its bottom 

 the water can be seen welling up in a great column, and it has 

 the same peculiar greenish blue of the other streams of this class. 

 No live oaks or other trees surround it, and it stands alone, a 

 great fountain in the desert." These springs occur at intervals 



