June 26, 1885.] 



SCIENCE 



529 



cesses employed, the book is well supplied with 

 authentic illustrations, although some of them 

 are not very clear, — a fault doubtless due to 

 imperfections in the original photographs. 



SOME STATE GEOLOGICAL REPORTS. 



Minnesota is not only the centre, but it is 

 also the summit of the continent, in the sense 

 of being the starting-point of the three most 

 important systems of drainage in North Amer- 

 ica. But, notwithstanding its geographic posi- 

 tion, the mean altitude of the state is less than 

 thirteen hundred feet, and its surface configu- 

 ration presents the simplicity and monotony of 

 a level and thoroughly glaciated region ; while 

 the geological structure of the greater portion 

 of the state is hopelessly buried under a thick 

 and almost unbroken mantle of drift. These 

 circumstances greatly diminish the labors of 

 the geologist ; and it is at first a matter of 

 surprise that ten years should have elapsed 

 between the inception of the survey and the 

 completion of this first volume of the final 

 report. But this is readily explained by the 

 very economical administration of the survey, 

 the geological corps consisting of the director 

 and one assistant, and, during a considerable 

 part of the time represented by this volume, 

 of the director alone. 



The introductory chapter is an extended 

 and admirable historical sketch of explorations 

 and surveys in Minnesota and the adjacent 

 states, from the times of Cham plain, Duluth, 

 Hennepin, and La Salle, to the present survey. 

 This historical introduction is, in its extent 

 and general interest, unique among American 

 geological reports. It is illustrated by several 

 good reductions of the earlier maps of the 

 north-west, and must prove a valuable com- 

 pilation to students of history and geography 

 as well as of geology. The account of the 

 general physical features of the state in this 

 volume is brief, and yet adequate, considering 

 the topographic uniformity. But we look in 

 vain for an}' generalized statement of the geo- 

 logical formations of the state below the drift. 

 It is probable, however, that this chapter is 

 reserved for a later volume ; for, as stated in 

 the preface, this volume is intended to be 

 mainly descriptive, — a repository of facts, 

 with only such generalizations as are self- 

 evident or generally admitted. 



The geology of Minnesota. Vol. i. of .the final report. By 

 N. H. Winchell, assisted by Warren Upham. Minneapolis, 

 Stale, 1884. 13+697 p., 1+31 pi. 4". 



Indiana. Department of geology and natural history. 

 Twelfth and thirteenth annual reports. John Collett, state 

 geologist. Indianapolis, State, 1883, 1884. 400 p., 38 pi. (4) 

 maps; 16+186 p., 39 pi., map. 8°. 



The popular demand for early practical re- 

 sults is well met in the excellent chapter on 

 the building-stones, which constitute, at pres- 

 ent, the most important field of the economic 

 geologist. The descriptions are plain and 

 simple, with the condensed statements of the 

 microscopic characters in fine print. The use 

 of ' syenite ' as a name for hornblendic granite 

 is, however, antiquated, and without the sanc- 

 tion of the leading lithologists of this country 

 and Europe. The table in which the descrip- 

 tions of forty-one of the most important build- 

 ing-stones are condensed and compared would 

 be a model of its kind, if the mineralogical 

 composition of the stones were included. It 

 shows at a glance, that, in crushing-strength 

 and durability, the building-stones of Minne- 

 sota are probably not surpassed by those of 

 any state in the Union. 



The main part of this volume (about five 

 hundred pages) is devoted to detailed accounts 

 of the geology of the state by counties. Of 

 the eighty counties in the state, twenty-eight, 

 including nearly all that part of the state south 

 of the Minnesota River, are here mapped and 

 described, two- thirds of this work being cred- 

 ited to Mr. Upham. In some instances the 

 descriptions of several counties have been 

 combined ; and, if this plan had been more 

 generally adopted, much needless repetition 

 might have been avoided, aud the monotony 

 of this part of the volume greatly relieved. 



The two annual reports of the state geologist 

 of Indiana contain comparatively little in the 

 way of original contributions to the geology 

 or natural history of the state. The most 

 important sections of the reports are those on 

 the paleozoic corals, and the subcarboniferous 

 fossils of Spergen Hill, by Professor James 

 Hall ; the paleozoic flora, by Professor Les- 

 quereux ; and the fauna of the Indiana coal- 

 measures, by Dr. C. A. White. These papers 

 consist of short specific descriptions, with 

 seventy-one plates of figures. Very few of 

 the species are new to science, or peculiar to 

 Indiana, while a considerable number are not 

 found in that state. These articles are really 

 compilations from the reports of other states 

 and more general sources ; and, although doubt- 

 less of some value as reference-manuals of the 

 paleozoic fauna and flora, it is a question to 

 what extent such publications are really ger- 

 mane to the purposes of a geological survey. 

 Each volume contains several short county 

 reports, and in these and other chapters the 

 economic features have special prominence. 

 But the treatment is not alwaj-s impartial, for 

 there is a manifest tendenc}' in some parts to 



