Roland Duer Irving — Chamhdrlin. 3 
commissioned assistant geologists and began his well-known 
investigations in that connection. Daring the first year he 
was assigned to the study of the Penokee iron range. He Avas 
here compelled, at the outset of his official career, to encounter 
unwarranted expectations raised by previous flattering opinions 
respecting the richness of the iron deposits given by incautious 
and inexpert explorers. His perfectly candid and unreserved 
report brought the usual reward of frankness and sincerity in 
the face of opposing desire, at first a storm of protest and of 
adverse criticism, which even threatened the existence of the 
survey, later, a sullen acquiescence in the truth, and finally, an 
admiration for the correctness and the courage of the position 
taken and a diversion of enterprise from unprofitable into suc- 
cessful lines of exploitation. In the second and third years of 
the survey professor Irving's held embraced the Paleozoic 
and Archaean strata of central ^A'isconsin. In the last years 
he returned to the lake Superior field and laid the broader 
foundation upon which nearly all of his subsequent investiga- 
tions were based. The results of his studies in this official re- 
lationship are recorded in the four volumes of the reports of 
the Wisconsin geological survey, (1873-1879). Meanwhile he 
had published several short articles in the American Journal of 
Science, the Trans, of the Wisconsin Academy, and elsewhere. 
Amo'ig these the more important are the "Age of the Copper- 
Bearing Rocks of Lake Superior and the Westward Continua- 
tion of the Lake Superior Synclinal.''* "Some new points in 
the Elementary Stratification of the Primordial and Cambrian 
Rocks of south central Wisconsin."! "The Stratigraphy of 
the Huronian Series of northern Wisconsin, and on the Equi- 
valency of the Huronian of the Marquette and Penokee Dis- 
tricts."J 
In 1880, professor Irving began those investigations upon the 
geology of the lake Superior region for the United States gov- 
ernment which continued until the time of his death. The first 
of these consisted of a comprehensive study of the copper- 
bearing series, the results of which he gathered into a mono- 
graph which perhaps stands as the best single expression of his 
*Am. Jour. Sci., vol. viir, Art. vii, p. 46, 1874. 
tAm. .Jour. Sci., vol. ix, Art. vii, p. 440, 1875. 
J Am. Jonr. Sci. vol. xvii, Art. xux, p. 393, 1879. 
