580 



SCIENCE. 



[N. S. Vol. XXI. Xo. 537. 



route followed, that of the El Paso and South- 

 western Railway, is particularly instructive as 

 giving an excellent section of the mesa and 

 the terraces bordering the Kio Grande. One 

 is strongly impressed with the evidence of dis- 

 integration of rocks due to the great diurnal 

 changes of the temperature, the work of wind 

 and of sheet-flood erosion, the production of 

 ' calichi ' or local tufaceous limestone by cap- 

 illary concentration of carbonate of lime, and 

 other phenomena too numerous to mention. 

 The railroad traverses several ' bolsens ' or 

 pocket deserts and the accompanying volcanic 

 cones and basaltic flows. The Chiracahua 

 Mountains of Arizona are the northern exten- 

 sion of the western Sierra Madres. The bol- 

 sens contain underground watercourses, and 

 this important fact has led the Phelps-Dodge 

 Company to establish the town of Douglas 

 beside the Mexican boundary in a large bolsen 

 lying east of their copper mines at Bisbee. 

 Comparatively shallow wells supply abundant 

 water for the great smelters of the Phelps- 

 Dodge and Calumet- Arizona copper companies. 

 The Phelps-Dodge Company gave our party 

 the courtesy of a special train for the purpose 

 of studying and photographing the phenomena 

 of the mesa for thirty miles along the El Paso 

 and Southwestern Railway. 



On Tuesday, February 14, the party left El 

 Paso and went southwestward into Chihuahua 

 over the Rio Grande, Sierra Madre and Pacific 

 Railway to the present terminus of the road 

 at Nuevas Casas Grandes. Fifteen miles 

 from El Paso the road reaches the top of the 

 mesa, and from there onward excellent studies 

 were made and photographs taken of the vast 

 llanos, the peculiar moving sand hills known 

 as ' los Medanos,' the lost mountains, and the 

 remarkable shallow lagunas, or periodical 

 lakes, without outlet, which receive the drain- 

 age from the Sierra Madre summits and form 

 the final settling pans for the wind- and water- 

 driven debris from the disintegrating moun- 

 tains. From Lake Guzman, the largest of 

 these lagunas, our route ascended the San 

 Miguel River, first through wide basin-like 

 valleys, then through deep, rugged, tortuous 

 canons, until finally its head waters were 

 reachfd on the undulating plains of the great 



Sierra Madre plateau more than 7,000 feet 

 above the sea, and 3,000 feet above the arid 

 plateau containing Lake Guzman. 



At Casas Grandes our party was shown the 

 great prehistoric ruins which gave the town 

 its name, by F. Mateus, the jefe politico of 

 the district, and at Colonia Juarez we were 

 hospitably entertained by Mr. Ivins, the presi- 

 dent of the prosperous colony of American 

 Mormons located there. At San Diego we 

 were guests at one of the great haciendas of 

 Gen. Luis Terrazas, governor of the state of 

 Chihuahua. For three days we traversed land 

 belonging to the same proprietor and were 

 brought into close realization of the tremen- 

 dous influence of the hacienda, or estate own- 

 ers, upon sociological conditions in Mexico. 

 For 300 miles eastward to the Conchas River 

 nearly every square mile of land is the prop- 

 erty of Governor Terrazas, and he is probably 

 one of the greatest individual landholders in 

 the world. 



From the terminus of the railway at Nuevas 

 Casas Grandes southward the journey has been 

 made on horseback and with pack train, and 

 the route thus far covered aggregates IfiO 

 miles. Most valuable studies have been made 

 of the remarkable igneous phenomena observed 

 en route; a collection of the rocks has been 

 made for the American Mus'eum of Xatural 

 History, and photographs have been made 

 illustrating every phase of the physiography, 

 geology and vegetation of the region traversed. 



After leaving the impressive caiion of the 

 San Miguel our journey lay across the high 

 plateau for about fifty miles to the new town 

 of Dedrick, consisting of one habitable log 

 house and several others in process of con- 

 struction in the midst of the great forest of 

 long-leafed yellow pine which characterizes 

 the plateaus and peaks from 7,000 to 8,000 

 feet in elevation. Immediately west of De- 

 drick the plateau is scored by the gi-eat canon, 

 ten miles wide and nearly a mile deep, of the 

 Yaqui River, here known as the Aros. This 

 streamway is one of the most stupendous 

 scenic features imaginable, and in beauty and 

 grandeur rivals the famous Grand Canon of 

 the Colorado. Guaynopita is a little mining 

 camp on the mountainside, four hundred feet 



