336 The Cincinnati Nocks. — Pernj. 
This does away entirely with the deep-sea idea. It also 
does away with the transportation theory to account for the 
shale, which seems under the circumstances to be not at all 
borne out by the observed facts. It, however, assumes a 
shallow sea, even at times extending to land conditions. This 
sea must have been in nearly all parts shallow enough to be 
affected at its bottom by surface waves, and in many eases 
shallow enough to leave the imprint of these waves in charac- 
ters so strong as not to be easily misunderstood. 
That the constituents of the strata must have been orig- 
inally derived from the land, is undoubtedly true, but they 
came in the form of solutions, and not, as some have supposed, 
in finely divided particles transported b}' streams. 
The necessity of numerous alternate uph£avals and depres- 
sions of the forming continent is no longer apparent, but 
another factor seems demanded, viz : a gradual sinking of the 
area during this period. My own idea is that this sinking 
about kept pace, with the upward growth of the strata, so that, 
except in a few instances which might be cited, the generally 
shallow character of the water was not much changed until 
near the end when the great upheaval that gave rise to the 
Cincinnati axis put a stop to further aqueous growth and 
changed the condition from — shall I say an ainphibious to 
one of dry land? 
If this reasoning be correct, every stratum of limestone, 
with its accompanying shale constitutes indubitable proof of 
a shallow sea. How deep this sea may have been in its deep- 
est portions it is impossible to tell, but as I am told by old 
lake Erie pilots that after storms on the lake the whole sheet 
of water becomes muddy, we may conclude that portions of 
the Cincinnati sea may have been at least as deep as lake 
Erie. 
Cincinnati, Aug. 19th^ 1889.^ 
The Spanish term adohe has been adopted by I. C. Russell 
as a scientific designation for the peculiar superficial calcar- 
eous clay, or loess, that is generally distributed in the valleys 
of the "arid regions." It is extensively used by the Indians 
and the Mexicans in making sun-dried brick. — GeoJ. Mag. 
July, 1889,]). 291. 
