202 TJic America?i Geologist. April, i9Cfi 
Survey of Ohio in 1884, on the Stratigraphical Order, together 
with chapters II and III on the Lower Coal Measures of Ohio^ 
constituting the first 300 pages of the volume, in which this 
harmony with the Pennsylvania column is so conclusively 
shown and the entire series traced from the eastern margin 
of the state clear across the same to the Kentucky boundary, 
will remain the master piece of Dr. Orton's purely geologic 
work, although his contributions to the geology of petroleum 
and natural gas in Volume VI, published in 1888, are of almost 
equal importance. 
The reader will pardon another personal reference to my 
own work in connection with Dr. Orton's valuable services to 
science in the geology of petroleum and natural gas. The 
writer had published the "anticlinal" or structural theory of oil 
and gas in the issue of "Science" for June 26th, 1885. The 
conclusions there announced were at once violently attacked 
by several of his confreres upon the Pennsylvania Geological 
Surv'ey, whose work had been largely in the oil fields of the 
state, and hence it was but natural that geologists in general 
should give much heed to the opinions of those who opposed 
his deductions. At this critical period of the discussion, Dr. 
Orton, ever seeking the truth, without bias from any source, 
after carefully submitting the claims of the structural theory 
to the facts in Ohio geology, announced his conviction of the 
truth of the theory, and gave, in Vol. VI, of the Ohio geologi- 
cal reports, and in other papers, such beautiful and practical 
applications of the same to the oil and gas fields of Ohio., 
couched in the vigorous, lucid and convincing style which 
characterizes all his writings, that the opponents of the struc- 
tural theorv abandoned the field of contention, and thus its 
adoption, brought about largely through Dr. Orton's work 
in Ohio, Kentucky, New York, Kansas and other states, ha.s 
become almost universal both with geologists and the prac- 
tical operators for oil and natural gas. 
Rev. Washington Gladden, for many years Dr. Orton's 
pastor and intimate friend, in a memorial address delivered at 
the P^irst Congregational church, of Columbus, on the even- 
ing of November 5th, 1899, upon the life and character of his 
deceased friend, has so aptly depicted many of his personal 
characteristics, that they find here an appropriate place. He 
