December 20, 1889.] 



SCIENCE. 



423 



remedied when Connecticut and Rhode Island are added to it, as 

 they may be in a few years ; the field-work being completed for 

 Rhode Island, and well under way for Connecticut. The water is 

 printed in blue ; the contours, in brown ; the names, boundaries, 

 railroads, and meridians and parallels, in black. The map is a 

 handsome piece of work, but it is questionable if a finer effect could 

 not have been produced by using a dark gray to indicate the cul- 

 tural work ; for the black is in too great a contrast with the rest to 

 give satisfaction to the eye. 



The larger physical features of the State ai'e brought out with 

 much clearness. The gradual ascent inland from the coastal low- 

 land to the uplands can be traced quantitatively now for the first 

 time on a map. The upland surface is, to be sure, greatly broken 

 by valleys, but the general accordance of summit altitudes and 

 their progressive increase westward are so well marked that they 

 are best interpreted as remnants of an old lowland, nearly plain, — 

 a "peneplain," as it might have been called, — now moderately 

 elevated and inclined eastward, and much worn by subsequent 

 valley-cutting. Very few hills rise distinctly above the surface of 

 the old peneplain ; Blue Hills near Boston, Wachusett between 

 Worcester and Fitchburg, and Greylock in the north-western 

 corner of the State, being the most conspicuous examples of such 

 forms. The mountains of Berkshire are generally but little higher 

 than the e.xpanded surface of the plateau next eastward, and have 

 gained their present bold relief by the wasting-away of the limestone 

 valley floor. In the same way the trap ridge of Mount Tom and 

 the conglomerate mass of Mount Toby stand above the floor of the 

 deep and broad Connecticut valley that has been excavated by this 

 ancient river in the soft triassic shales. 



The contrast of form between upland and valley gives corre- 

 sponding contrast in the villages built at high and low levels. Hub- 

 bardston. Petersham, and Royalston on the central plateau, east 

 of the Connecticut valley, stand just above the contour line of 

 1,000 feet. Blandford, Worthington Corners, and Heath, on the 

 western plateau, are over 1,500 feet. The hills rise little above 

 the open country far and wide around these airy settlements, but 

 the valleys are sunk deep below them. All the larger villages, 

 and most of the factories of the plateau region are in the valleys ; 

 but the shoe-shops climb to high levels in Spencer and North 

 Brookfield. The railroads follow the valleys as far as possible, and 

 have no high bridges ; this being characteristic of railroad con- 

 struction on an upland so far consumed by river-work. In west- 

 ern Pennsylvania and New York, where the upland is more con- 

 tinuous and the valleys correspondingly narrower, many railroads 

 run on the high ground, and then have to cross the river-trenches 

 in lofty viaducts. 



The wide valleys of Berkshire and the Connecticut River, opened 

 on weak rocks, are cultivated in broad, smooth fields. The narrow 

 transverse valleys of the adjacent plateaus, cut across the hard 

 rocks, have steep rocky slopes and mere strips of gravelly bottom- 

 land. The Deerfield, Westfield, Miller's and Quaboag Rivers show 

 these features most distinctly, as any traveller on the Fitchburg or 

 Albany Railroad may observe. The western plateau is drained in 

 a curious fashion by streams that rise close to its western margin 

 at heights above 2,000 feet, and traverse its entire breadth in direct 

 or oblique courses to the Connecticut valley. Its western slope 

 into the Berkshire valley is very abrupt. This suggests that the 

 Berkshire limestones were not so widely exposed on the surface of 

 the old peneplain as they are now ; and that then there was no 

 master-stream upon them, such as the Housatonic now is. If this 

 be correct, we must picture the drainage of the old peneplain low- 

 land as flowing eastward from the western border of the State to 

 the Connecticut valley, and must regard the Housatonic as a cap- 

 turing stream that grew northward by head-water gnawing, after 

 the old lowland was raised to something like its present height. 

 The short steep ravine streams that now drain the western slope 

 of the plateau follow inverted courses to the Housatonic ; and the 

 divides that separate them from the Connecticut tributaries must 

 be unstable, and slowly migrating to the eastward. A walk along 

 the margin of the plateau, past the heads of these ravine-streams, 

 ought to detect the characteristic consequences of such migration 

 in the form of the lateral secondary valley, that have been recently 

 diverted from eastward to westward outlet ; but the presence of 



drift in this region may complicate matters so far as to render such 

 analysis impossible. 



The presence of ponds and lakes is the most perceptible conse- 

 quence of glaciation. The eastern part of the State is perceptibly 

 blued over by them, but on the higher uplands they are relatively 

 rare. 



The separate quarter-degree sheets of larger scale, about fifty of 

 which will be required to cover the State, will receive special notice 

 when they are completed and published. W. M. D. 



BOOK-REVIEWS. 



Aspects of the Earth : A Popular Account of Some Familiar Geo- 

 logical Phenomena. By N. S. Shaler. New York, Scrib- 

 ner. 8°. $4. 



This is a superb reproduction in book form of the excellent 

 papers by Professor Shaler, that recently appeared in Scribner's 

 Magazine. There are sixteen full-page illustrations, besides nearly 

 a hundred in the text, the most of them copies of photographs in 

 the finest and most faithful style of wood-engraving. These tran- 

 scripts from nature the author believes to be more helpful to the 

 genera! reader than diagrams that require a schooled eye to appre- 

 hend. 



The topics of the chapters are " The Stability of the Earth," 

 "Volcanoes," "Caverns and Cavern Life," " Rivers and Valleys," 

 " The Instability of the Atmosphere," " Forests of North America," 

 and " The Origin and Nature of Soils." It is a good selection of 

 themes that at once possess a scientific interest and a popular and • 



practical bearing ; all, in fact, relating to the surface of the earth 

 or to phenomena more or less familiar to the public. The author 

 has made it his special purpose, in his own words, to choose sub- 

 jects that " commend themselves to the attention of intelligent 

 people," and " show the relation of natural forces to the fortunes 

 of man." 



The first chapter offers a satisfactory explanation in general of 

 earthquakes, though not emphasizing and illustrating the effect of 

 cumulative tension in the earth's crust, which might be compared 

 to that which is indicated by the cracking sounds of a stove-pipe 

 under the expansion of heat, or of a house under the contraction 

 of extreme cold. There is a full treatment of the facts in regard 

 to earthquake regions in the United States, especially as connected 

 with undisturbed pinnacles of rock and poised bowlders as indices 

 of long periods of rest. These may be admitted as proofs of the 

 absence of great earthquakes, but are hardly to be regarded other- 

 wise, inasmuch as a pinnacle, a wedged bowlder, or a " rocking 

 stone " might endure a good deal of oscillation. 



Volcanoes are referred to the superheating of water everywhere 

 permeating the crust to the amount of twenty per cent or more, — 

 a simple solution that is a relief to one's mind after all the theories 

 about descending sea-water, lakes of fire, and what not. Caverns 

 and cavern life, rivers and valleys, are treated with the freshness of 

 statement and illustration that characterize the entire volume ; and 

 while a theoretic item still under discussion is sometimes assumed 

 as fact, there is, for example, a candid remark that cave-life exhibits 

 modifications that cannot be caused by the competitive struggle 

 of existence, — an impartial remark in the noble spirit of Darwin 

 himself. The natural bridges, as that of Virginia, are explained as 

 remains of caverns. The caiions of the West are well accounted 

 for, and the cutting of rivers across mountains, also, but in a way 

 that would have been helped by the very apt illustration (in a 

 United States geological report) of a saw-log slowly rising against 

 a horizontal saw. 



The advocates of forest conservation have an ally in Professor 

 Shaler, who clearly sets forth the evils of denudation. It would 

 appear, however, that the destructive process goes on mostly in 

 wild districts, and that long settlement of a district tends to re- 

 store, and even to create groves where they were not. This last 

 tendency is strikingly manifest on the prairies in a few years after 

 occupation, and a manifestly changed climate follows. The loss 

 of a rich top-soil by washing, after the plough has broken up the 

 original protecting turf, is an evil that needs more attention. Is it 

 not possible to check this in a measure by so running the furrows 

 that these shall not be channels of waste, and to further avoid this 



