February io, 1910] 



NA TURE 



431 



though deriving much of its initial impulse from the 

 suggestion of British workers, from Hutton and Play- 

 fair to Ramsay, Jukes, Geikie, Jukes-Browne, and 

 Marr, has been organised and placed upon a systematic 

 basis, principally by the labours of workers like Penck 

 and Bruckner on the Continent, and the host of Ameri- 

 can geomorphologists, foremost amongst whom 

 must be placed Davis, Salisbury, and Shaler. 



In the magnificently illustrated volume before us, 

 Prof. Salisbury and Mr. Attwood have attempted to 

 show how a topographic map may be made to yield 

 up all its secrets. The first section of the preliminary 

 letterpress is substantially that which appears in the 

 explanation of each fasciculus or folio of the geologic 

 map of the United States. It sets forth the nature 

 of the features delineated in the three categories of 



mostly on the scale of about one inch to the mile 

 {1/62,500 instead of 1/63,360), of actual pieces of 

 country, and in most cases by pictorial illustrations. 

 The maps are beyond all praise for the beauty of 

 their execution and the admirable printing; indeed, 

 the contrast between the splendid series of maps of 

 which these are specimens selected merely because 

 they portray typical features of topography, and our 

 British maps, inferior in delicacy, heterogeneous in 

 stvle, badly printed on poor paper, is very humiliating 

 to our national pride. The contour lines are beauti- 

 fully engraved, and are drawn at intervals of 20 feet, 

 whereas the i-inch maps of the British Isles, with the 

 exception of a portion of a single sheet, that embracing 

 Longridge Fell in Lancashire, have contour-intervals 

 of 100 feet, and even our 6-inch maps are contoured 



A Tidal Lagoon formed by sand spit at the mouth of San Luis Obispo Creek, Cahfo I 



(i) water (blue), (2) relief (brown), and (3) culture 

 (black). The last term might easily be misunder- 

 stood by a British reader — it does not refer to cultiva- 

 tion only, but to all the signs of man's handiwork, 

 such as roads, railways, buildings, boundaries, that 

 appear upon the maps. The geological details are, of 

 course, expressed bv the conventional signs and colours 

 adopted by the national service. 



The succeeding sections deal with elementary con- 

 cepts of relief, followed by a succinct discussion of the 

 various agents of change and their effects, under the 

 headings wind, stream-erosion, alluviation ; topo- 

 graphic forms resulting from unequal hardness of 

 rocks, erosion cycles, stream piracy and adjustment, 

 topographic effects of ground-water, glaciation, coast- 

 lines, volcanism, faults, special types of lakes. Each 

 of these subjects is illustrated by one or more maps, 

 NO. 2102, VOL. 82] 



onlv at the same intervals, saving those of the for- 

 tunate counties of Lancashire and Yorkshire, the sur- 

 veys of which had been accomplished prior to 1858, 

 when the depreciation of our maps was decreed. 



If anv adverse criticism were offered of this ad- 

 mirable manual it would be that the landscape illus- 

 trations do not in all cases represent the area or even 

 the district shown upon the map, though illustrating 

 similar plienomena, or, where the area is the same, 

 the point of view cannot be identified. These are 

 small defects in a work that cannot fail to be of the 

 utmost value to students and teachers the world over, 

 and particularly to those of America, for whom it is 

 designed, and those of Britain, who may have a cen- 

 tury or two to wait for the materials out of which 

 a similar memoir could be prepared for our own 

 country. P. F. K. 



