AMERICAN GEOLOGY DECADE OF 1870-1879. 



571 



phy. He is represented as a modest, patient, and industrious man, 

 living- more for the service of others than for his own aggrandizement. 

 He died of heart trouble while alone on a lake near Oconomowoc, 

 Wisconsin. 



Lapham was succeeded, as above noted, by O. W. Wight, who served 

 but one year (1875). His one report of progress was not published at 

 the time, but was likewise included by Chamberlin in the second vol- 

 ume of the final reports, bearing date of 1877. It contained matter of 

 little other than historical interest. 



In February, 1876, Prof. T. C. Chamberlin was placed in charge of 

 the State survey. The organization continued in existence until 1879, 

 the final reports appearing in the form of four royal octavo volumes, 

 dated, respectively, Vol. I, 1883; Vol. II, 1877; Vol. 

 of h ^sc e oS S i U 87 V 6 ey HI, 1880, and Vol. IV, 1882. comprising altogether 

 3,035 pages. 

 The principal assistants on the survey 

 were R. D. Irving, F. H. King, Moses 

 Strong, E. T. Sweet, J. D. Whitney, and 

 L. C. Wooster. R. P. Whitfield served as 

 paleontologist. Aside from acting as di- 

 rector of the survey, Chamberlin himself 

 took charge of the geology of eastern 

 Wisconsin, of which he described in con- 

 siderable detail the hydrology, the soils. 

 and the glacial drift. The so-called Kettle 

 Range he believed to be in part moraines, 

 and the kettle holes to be due mainly to the 

 melting of masses of ice buried in the grav- 

 els. He discussed the economical value of 

 the clays and shell marls of the region, and 



for the first time in America demonstrated the usefulness of the 

 microscope in examinations of detrital rocks. In this connection he 

 noted that a microscopic examination of the sand grains of the Pots- 

 dam sandstone was entirety fatal to the view still occasionally advanced 

 to the effect that such were produced by crystallization from solution. 

 He, in his turn, however, failed to recognize the possibility of the 

 crystalline form of some of the granules being due to secondary 

 enlargement (see pp. 469 and 553). 



The oolitic iron ore lying between the Cincinnati shales and the 

 Niagara limestone was thought to be undoubtedly a marine deposit laid 

 down in detached basins. It was shown, further, that the three well- 

 marked classes of limestone occurring in the southeastern counties of 

 Wisconsin graded into each other and were doubtless formed contem- 

 poraneousl} T , the residual mounds or ridges being ancient coral reefs, 

 while the o-ranular sand rock was formed from calcareous sands 



U— Thomas Crowdef Cham- 

 berlin. 



