Part I. Report of progress in 1869, by J. S. Newberry, chief geologist. Part II. Report of progress in the second district, by E. B. Andrews, assist. geologist. Part III. Report on geology of Montgomery County, by Edward Orton, assist. geologist.

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At Toledo the rock surface is 140 feet below the lake. An excavated
trough runs southward from Lake Michigan to the north line of Iroquois
county, Illinois; thence south-west through Champaign county, beyond
which point it has not been traced. Its western margin is very sharply
marked at Chalsworth, Livingston county, where it has a depth of 200
feet, and reaches to the Cincinnati group. Farther north its bounding
walls are composed of Niagara limestone, which forms buried shoulders
on the Calumet and Kankakee rivers. At Bloomington this trough acquires a depth of 230 feet, and it then contains one or more strata of
carbonaceous earth, with trunks of trees supposed to represent ancient
soils. Where penetrated in other localities the depth of this channel is
from 75 to 200 feet, and it is filled with clay, sand, gravel, etc., (Prof. J.
H. Bradley.)
The rock bottoms of the troughs of the Mississippi and Missouri, near
their junction or below, have never been reached, but they are many feet,
perhaps some hundreds, beneath the present stream beds.
The borings for oil in the vallies of the western rivers have enabled me
not only to demonstrate the existence of deeply buried channels of excavation, but, ip some instances, to map them out. Oil Greek flows from
75 to 100 feet above its old channel, and that channel had sometimes
vertical and even overhanging cliffs. The Beaver, at the junction of the
Mahoning and Shenango, runs 150 teet above the bottom of its old trough.
The Ohio, throughout its entire course, runs in a valley which has been
cut nowhere less than 150 feet below the present river.
The Cuyahoga enters Lake Erie at Cleveland more than 100 feet above
the rock bottom of its excavated trough. The Chagrin, Vermillion, and
other streams running into Lake Erie exhibit the same phenomena, and
prove that the surface level of the lake must once have been at least 100
feet lower than now.
At New Philadelphia the Tuscarawas is running 175 feet above its
ancient bed. At Cincinnati the gravel and sand have been found to reach
over 100 feet below low water mark, and the bottom of the trough has
not been reached. At the junction of the Anderson with the Ohio in
Indiana a well was sunk 94 feet below the level of the Ohio before rock
was found (Hamilton Smith.) At Steubenville the railroad bridge across
the Ohio is built on cribs, the rock bottom of the channel not being
reached. One of the pieis of the St. Louis bridge was sunk in sand and
gravel nearly 100 feet below the bottom of the Mississippi.
The falls of the Ohio, formed by a rocky barrier across the stream,
though at first sight seeming to disprove the theory of a deep, continuous
channel in our western rivers, really afford no argument against it; for
here, as in many other instances, the present river does not follow accurately the line of the old channel, but rklns along one side of it. At the
Louisville falls the Ohio runs across a rocky point which projects from