Alerander Winchell. 87 
thousand dollars, it is apparent that this was a year of unceasing 
activity. 
1860. In 1860 the work of the survey called him to spend 
most of the summer season in camp around the lake shores. He 
was able to cojrdinate the salt wells at different points along the 
Saginaw river. The leisure of the year was occupied by paleon- 
tological investigations. } 
1861. His Report of Progress of the Geological Survey, an 
octavo volume of 339 pages, was published in August, 1861. 
In this he fully anticipated the vast development of the salt inter- 
est in the Saginaw valley. In consequence of the outbreak of 
the war the Legislature made no provision for the continuance of 
the survey, but the paleontological investigations were carried on 
privately through the year. As with all surveys the Michigan 
survey entailed on the director a burdensome correspondence relat- 
ing to possible and projected economic measures in various parts 
of the state. One only need here be mentioned. ‘lo an appli- 
cant for information respecting the existence of gypsum in the 
vicinity of Tawas, he indicated a ridge near the lake shore, which 
he had inspected during the season’s examinations (not the well- 
known outcrop by the water's edge further south) as a locality 
containing probably a large supply of gypsum. Some experi- 
menters had already pronounced the locality barren; but his cor- 
respondent, taking a location for the price of an old gun, sold it, 
after the discovery of 18 feet of pure gypsum, for some thou- 
sands of dollars. On this spot has since been developed one of 
the finest gypsum quarries in the world. 
1862-63. His special paleontological study was directed 
toward the series of strata which he had designated the ‘‘Mar- 
shall group,” a Carboniferous assemblage which had been regarded 
by American geologists as the equivalent of the New York 
Chemung. He published a communication on these rocks in the 
Amer. Jour. Sci. [2], vol. xxxu, p. 353, which contained his 
first descriptions of new species. Further descriptions were pub- 
lished in the Proceedings of the Acad. of Nat. Sei. Phil. for 
Sept., p. 405. He also published an article in Hunt’s Merchants’ 
magazine for September, on The Salt Manufactureof the Saginaw 
Valley Researches in the Marshall group were continued through 
1865, and the following articles were published: On the Identifica- 
tion of the Catskill Red sundstone group with the Chemung (Am. 
