September 28, 1888.] 



SCIENCE. 



149 



scale and more accurate and elaborate maps has in great measure 

 been offset by more economic and more efficient service, resulting 

 from constantly growing experience and skill in field and office 

 work." 



Yellowstone Park. 



" Under the charge of Dr. Arnold Hague," says Director Powell, 

 after treating of several other topics, " the survey of the National 

 Park has made much progress. A topographic map of the Mam- 

 moth Hot Springs basin has been made by Mr. Anton Karl of the 

 topographic corps, and maps of the other geyser basins have been 

 completed. Dr. Hague's geologic work has been prosecuted in the 

 eastern portion of the park, in the comparatively little-known area 

 around the northern part of the Wind River Range and the Absa- 

 roka l\ange, which constitute some of the grandest features of the 

 region. His inquiries have thrown much light on the geologic his- 

 tory of the features of the park, and of the volcanic processes which 

 produced such wonderful results. Many instructive studies have 

 been made of the action of the geysers and the hot-springs, and of 

 the mineral deposits to which they have given rise. 



" Dr. Hague's attention has been forcibly drawn to the impor- 

 tance of this reservation as a storage-area for the head waters of 

 some of the largest upper tributaries of the Missouri, and also of 

 the Snake River. Yellowstone Lake is the largest natural reservoir 

 of the Rocky Mountain region, and may be made an important fac- 

 tor in the prosperity of future populations of the country adjoining 

 the lower courses of the Yellowstone, who will be dependent upon 

 its waters for irrigation. Dr. Hague has devoted much time to the 

 investigation of this important subject, and has obtained informa- 

 tion which cannot fail to be of great value in the future delibera- 

 tions of Congress upon questions relating to its policy towards the 

 public lands upon this broad watershed of the continent." 



Atlantic Coast Work. 



" The examination of swamps and marsh-lands," continues 

 Major Powell, " has been continued during the past year under the 

 charge of Prof. N. S. Shaler. The large area of such lands along 

 the Atlantic coast south of New York, and their situation upon the 

 coast-line, make them especially important, and even a subject of 

 solicitude in relation to the future development of the country. 

 Deleterious to health in their natural condition, an obstacle in the 

 way of approach to the sea, repellent to the settler, to agriculture, 

 and to manufacturers, they yet hold out the hope of highly produc- 

 tive utilization through the judicious application of capital. Wher- 

 ever they are susceptible of effective drainage, they are generally 

 among the most valuable lands for agricultural purposes, and their 

 unhealthful condition is ameliorated, or even wholly remedied. 

 There are over 100,000 square miles of such land in the United 

 States, a large proportion of which, by good engineering, can be 

 rendered highly productive. Much of it abounds in peat or iron 

 ores, and in South Carolina and Georgia it contains the products of 

 phosphates, which are collected and treated in chemical works in 

 steadily increasing quantities. The swamps and overflowed lands 

 of the interior present analogous conditions. Professor Shaler has 

 visited the Everglade region of southern Florida, along the coast, 

 to ascertain the general facts with reference to the possibility of 

 drainage, and with highly encouraging results. He has investi- 

 gated such evidences as were accessible, bearing upon the origin of 

 the topographic features of the south^n part of the peninsula, and 

 especially those which are indicative of elevation or subsidence of 

 the land in recent geologic time. He has also made a preliminarj' 

 study of the phosphate deposits of South Carolina, and the results 

 have been put in form to be published as a bulletin of the Survey. 



" Progress has been made in mapping the swamp districts of 

 Massachusetts, and Professor Shaler has completed the mapping 

 of those occurring in the vicinity of Abington and Newbur)port. 

 A large amount of special geologic work, bearing upon particular 

 questions now under investigation, has also been done under Pro- 

 fessor Shaler." 



Archaean Geology. 



" In many parts of the United States extensive e.\posures of very 

 ancient strata occur, embracing in some cases formations which 

 are older than the oldest fossiliferous rocks of assignable age. In 

 •other cases there are formations of the same ages as some of the 



fossiliferous beds, but in a condition which indicates that they have 

 undergone great changes since their deposition. Not only have 

 their component beds been tilted, bent, folded, dislocated, and dis- 

 torted to extreme degrees, but their mineralogic contents and their 

 textures have been more or less altered. One effect of this meta- 

 morphism has been the obliteration of any fossils they may have 

 contained originally, upon which the geologist mainly relies in de- 

 termining the ages and relations of strata. The confusion into 

 which these masses have been thrown by the forces which have 

 fractured and distorted them has increased the difficulty. 



" The present state of knowledge relating to the origin, relative 

 ages, and former condition of these strata, to the nature of the pro- 

 cesses which have wrought these profound changes in their consti- 

 tution, and to their relation with each other, is very unsatisfactory, 

 although no rocks have been more earnestly studied. While the 

 knowledge which has been gained is vast in amount, and highly 

 useful in its way, it has not been of such a character that it could 

 be grouped and generalized into broad inductions, and it has thrown 

 comparatively little light upon the most important questions. 



" There are large areas in the United States where these rocks 

 are exposed. The most extensive are in the New England States, 

 the southern Appalachians, the vicinity of Lake Superior, and many 

 parts of the great mountain region of the West, and especially the 

 ranges upon and near the Pacific coast. It is deemed of impor- 

 tance to the interest of geologic science in general — both of sys- 

 tematic and economic geology — to take up this subject and pros- 

 ecute investigations of the older crystalline rocks with vigor. The 

 two fields which are regarded as offering the best opportunities and 

 prospects for these investigations are the New England States and 

 the Lake Superior region. In the former field. Prof. R. Pumpelly 

 has been diligently at work with several assistants. Convinced 

 that the Green Mountains of Vermont and Massachusetts are more 

 likely to yield desired results and to clear up the broader questions 

 relating to the geology of New England, he has divided the country 

 into zones across those mountains, and is prosecuting the investi- 

 gation of their structure in great detail. He has already ascer- 

 tained the components of the Green Mountain series of strata, has 

 gained considerable knowledge of their lithology and relations, and 

 has made much progress towards unravelling their complicated 

 structure, and learning the processes by which their metamorphism 

 has been effected." 



After a brief account of the investigation of corresponding hori- 

 zons in the Lake Superior region, closing the notice with a deserved 

 tribute to the late Prof. Roland D. Irving, who was in charge of 

 this work, and who died in May last, Major Powell passes to a 

 brief review of the work done during last year in the glacial divis- 

 ion. 



Glacial Geology. 



" The study of the vestiges of glaciation," says the director, " has 

 been conducted by Prof. T. C. Chamberlin. The New England 

 States, New York, a large part of Pennsylvania, and in general the 

 States north of the Ohio River and east and north of the Missouri, 

 constitute a region whose superficial deposits and soils, whose lakes 

 and minor topographic features, have been profoundly modified, and 

 in great part made what they now are, by the action of glaciers. 

 This region, as well as the basins of the Great Lakes and the Cana- 

 dian Provinces indefinitely northward, was doubtless during a recent 

 geologic period sheeted over with ice in a manner which finds a 

 counterpart in the present condition of Greenland. This conclusion 

 — and a similar one has been reached with respect to certain por- 

 tions of Europe — rests upon a vast mass of circumstantial evidence 

 so clear and convincing, when fully understood, that it may be re- 

 garded as one of the most wonderful and pleasing examples of 

 inductive reasoning, and one of the best established that the whole 

 realm of modern science affords. Professor Chamberlin's work has 

 been the investigation of the extent of this former field of ice and 

 its boundaries, the nature of its action in shaping surface features, 

 the chief incidents of its history, and the geologic and climatic, 

 changes which were associated with it, whether as causes or 

 effects. 



" Near the close of the glacial period there existed, in the region 

 now embraced in the valley of the Red River of the North and that 

 of the Saskatchewan, a great lake, to which the name of Lake Ag- 



