Geological Survey of the State of Ohio. 349 
of fuel for all the people of this state, both for domestic and manufacturing 
purposes ; and, if we allow double this amount for prospective consump- 
tion, in consequence of increased population and manufactures, we have 
coal within a moderate depth, sufficient for consumption during 2,500 
years. If we consider the value of coal as a means of motive power in 
propelling machinery, each acre, of the 5,000 square miles of coal, con- 
tains stored and ready for use, a power equal to that of one hundred and 
ninety two men for one hundred years, working ten hours per day. Al- 
lowing a profit of only twenty five cents on each cubic yard of coal, an 
acre would yield a profit of more than $2,000 where a depth of six feet is 
““These facts will, it is hoped, lead our citizens to appreciate the vast 
mineral resources in this valuable combustible, with which our territory 
through Infinite Wisdom, is so bounteously supplied.” pp. 5, 6, 7. 
The estimate is very far too low, not only as to the area, trav- 
ersed by the coal, but its mean thickness. As many as six dis- 
tinct beds or seams of workable coal crop out successively, as you 
travel from east to west. ‘These beds vary in thickness from 
24 to8 feet. Thus, we think that 20 feet of workable coal, over 
an area of 8,000 square miles, would be a nearer approximation to 
the truth. 
But perhaps the most interesting fact in this report, in a geolo- 
gical point of view, is the degradation of the land, bordering on 
Lake Erie. In many places, the encroachment of the lake has 
been so rapid, within a few years, as to become a formidable evil. 
From the difficulty of opposing a barrier to these encroachments, 
many towns are threatened with demolition. 
‘The shore at Cleveland is washing away rapidly in front of the town. 
The cliffs, undermined by the surf and land springs, crack off at the top 
and slide partly down, so as to come within the action of the surf, while 
other slides from above, continue to push it farther and farther into the 
lake, until all is carried away by the waves and shore currents. Slides 
Occur every year. Several rods, in width, have slidden down and been 
Washed away within a few years. 
“ Attempts have been made to arrest this degradation, which threatens 
to remove the site of the city in the course of a century or two, unless it 
be checked. If piers be erected at intervals, extending out for one hun- 
dred to one hundred and fifty yards from the shore, and well filled in, allu- 
vial deposits from the sand swept coastwise by the surf and shore currents, 
will necessarily be deposited in the eddies formed by these obstructions. 
An example of the application of this principle may be seen on the west 
side of the pier which protects the harbor, where several acres of alluvial 
