22 The American Geologist. January, 1894 
yet observed in Wisconsin.'*'" The age assigned to this rock 
was contested by Dr. (). AV. Wight in 1875,f but again »the 
judgment of Lapham lias been vindicated, in the discovery of 
many Hamilton species in tbe vicinity of Milwaukee, in addi- 
tion to the fish remains first noted. At a later date. July. 
L874, Dr. Lapham compared this rock with the water-lime- 
stones of Louisville. Ky.,J with a suggestion as to it- possi 96 
ing the same useful qualities. This suggestion has also been 
verified, the average tensile strength of the Milwaukee ce- 
ment, at the end of seven days, being, according to Gen. Q. 
A. Gilmore, 64* pounds to the square inch, and that of the 
standard brands of five of the Rosendale companies being 47 
pounds. 
The principal event connected with Dr. Lapham' s life, hav- 
ing a geological bearing, was his appointment as "chief geol- 
ogist" of the state survey, ordered in 1873 by the Legislature 
of Wisconsin. He served about two years and rendered two 
reports of progress. These are published in the second vol- 
ume of the final report of this survey, recently concluded 
under Prof. T. C. Chamberlin. These reports, while not con- 
taining much original matter that can be referred to Dr. 
Lapham's direct agency, yet reveal at once the broad grasp 
which he had taken of the contemplated work and the effi- 
cient executive management and practical turn which his 
conduct of the survey would have imprinted on its progress 
and its results. His report for 1873 summarizes the work of 
the year. His aids were Profs. R. 1). Irving, T. C. Chamber- 
lin and W. AV. Daniells, and Mr. Moses Strong. The work of 
each is epitomized in clear, concise language. He then adds 
a long list of railroad levels, a catalogue of the known miner- 
als of the state, gives many analyses of mineral waters, and 
tables of the annual rain-fall at Milwaukee from Ls41 to 1873, 
from records mostly kept by himself, the grand average be- 
ing 30.27 inches. He treats briefly of the relations of the 
survey to the United States Coast and Geodetic Survey, and 
to agriculture. It was through his initiatory recommenda- 
*Am. Jour. Sci., (2) xxix, p. 145. 
tGeology of AVisconsin, vol. n, p. 79. 
JWalling's Atlas of AVisconsin, article Geology, July, 1874. 
