Novembers, 1895.] 



SCIENCE. 



619 



upward movements of the region ; the effect 

 of the earliest movement having now been 

 propagated nearly to the head of the stream, 

 while the latest elevation has caused a deep- 

 ening of the vallej' only near its mouth. 

 (The lateral terraces that might be expected 

 if this explanation were true are not men- 

 tioned.) The extremely meandering course 

 of many deep valleys in the plateau is as- 

 cribed to lateral erosion on convex curves of 

 originally irregular courses, and not to per- 

 petuation of meanders originally developed 

 on upland surface and somewhat increased 

 during the incision of the present val- 

 leys. 



THE RIVERS OF SPAIN. 



This large subject is treated in a descrip- 

 tive manner, with especial reference to the 

 value of rivers for irrigation and naviga- 

 tion, by E. Torres-Campos (Bol. Soc. geogr. 

 Madrid, xxxvii., 1895, 7-32, 81-140). The 

 excessive aridity of many river basins and 

 the dependence of agriculture on irrigation 

 are the themes of many pages. In the 

 basin of the Ebro, for example, irrigating 

 canals create productive farms, sustaining a 

 dense population ; but away from the streams 

 there is neither tree nor bush, and one may 

 there travel ' leagues and leagues ' without 

 seeing the trace of human habitation. The 

 dryness of this region has obliged many of 

 the laboring classes to emigrate. Some go 

 to South America, some to France; and the 

 improved condition of the few who return 

 stimulates the departure of others. On 

 parts of the coast of Valencia the streams 

 from the mountains have built out a sloping 

 plain of fertile alluvium, where the construc- 

 tion of roads and canals has been so easy 

 that the region is occupied by a prosperous 

 and progressive population. No considera- 

 tion is given by the author to the origin of 

 the rivers or to the present stage of their 

 development. W. M. Davis. 



Haevabd Univeesity. 



SCIENTIFIC NOTES AND NEWS. 

 FIELD WORK OF U. S. GEOLOGICAL SURVEY. 



Director Walcott, of the U. S. Geo- 

 logical Survey, has returned to AVashing- 

 ton, after a two months' absence in the 

 northern Rocky Mountain region, spent in 

 field work. He was studying the Cambrian 

 rocks and faunas of Montana and Idaho. 



The field work of the season is drawing 

 to a close. ISTearly all the geologic parties 

 have come in, though work is still going on 

 on the Pacific coast, and, to a small extent, 

 in the Interior or Mississippi basin. Work 

 in the northern Rocky Mountain region 

 and in Washington was brought to a stop 

 early in October by severe storms. In 

 this region Mr. Emmons and Mr. Willis 

 were at work as well as the director. The 

 special work in Alaska, an examination of 

 the gold and coal resources, was advanced 

 so far as conditions would permit, and Drs. 

 Becker and Dall are now in Washington 

 preparing their joint report on the subject. 

 Since submitting to the Secretary of the In- 

 terior his report on the character of the 

 lands involved in the McBride claim in 

 Washington, Mr. W. Lindgren, who made 

 the expert examination for the Government 

 in that case, has been mapping the geology 

 of the mining region of northern-central 

 California. 



Topographic work is still in progress in 

 all quarters. The number of sheets sur- 

 veyed is unusually large and the work is 

 generally of excellent character. Surveys 

 are, or ha^J^e been, in progress in about 

 twenty-five States and Territories. The 

 Chief Topographer, Mr. Henry Gannett, 

 made an inspection of the work, especially 

 that in the West. The work going on in 

 Indian Territory is of special interest be- 

 cause of the peculiar conditions governing 

 it. Here, in connection with the regular 

 topographic mapping, a subdivisional or 

 parceling survey is being made in the in- 

 terest of the General Land Office. This 



