Review of Recent Geological Literature. 113 
The monoclinal attitude of the formation, with a general eastward 
dip of twenty or thirty degrees, is found to be due to faults which ex- 
tend nearly paralhd with the strike, having their upthrow on the east 
in practically all observed cases ; but there are departures from the 
eastward direction of dip in the neighl)orhood of the curved trap ridges 
at some other points. In explanation of the mechanical origin of this 
monocline, the author shows that the disturbance occurred after the 
deposition of the Triassic beds was essentially completed, and there- 
fore involved the whole thickness of the formation ; and that the faultB 
doubtless have dejith proportionate to their throw and length, carry- 
ing them far down, perhajjs many miles, into the underlying schists 
and gneisses. An ingenious series of diagrammatic sections illustrates 
how the originally horizontal Triassic strata and the steeply inclined 
schists beneath have been disturbed by lateral compression, exerted 
in an east and west or southeast and northwest direction, producing 
the monoclinal structure and the frequently crescentic forms of the 
ridges of outcropping trap sheets. 
Salt-making processes In the United States. By Thomas M. Chat.vrd. 
Pages 491-535; plates liii — Iv. (Accompanying the seventh report, U. 
S. geological survey.) 
This paper treats of the chemistry of brine, and describes the differ- 
ent methods of salt-making employed in this country and the results 
obtained by them, together with some references to foreign practice- 
The author concludes that, as a whole, the salt industry of the United 
States, while conducted with energy and skill, is yet capable of much 
better work than that done at present. An appended table shows the 
results of analyses and experiments, made under the direction of Wal- 
ter R. Johnson of the U. S. navy, testing the heating, evaporating and 
steam-producing values of thirty varieties of coal from the United 
States, three from Nova Scotia, and three from Great Britian, also of 
dry pine wood. 
The Geology of the Head of Chesapeake Bay. By W. J. McGee. 
Pages 537-646 ; plates Ivi-lxxi ; figures 109-114. (Accompanying the 
seventh report, U. S. geological survey.) 
The specific object of the investigation here reported was to deter- 
mine the probable success of an artesian boring at Fishing Battery 
station in Chesapeake bay, near its head, between Havre de Grace and 
Spesutie island. A detailed map shows the distribution of the Colum- 
bia formation in the vicinity of the head of this bay ; and another on a 
small scale shows the drainage of the middle Atlantic slope, with the 
course of the fall-line, where the streams pass their lowest rapids or 
falls. This line, whicii extends close along the northwest side of this 
part of Chesapeake bay from Baltimore to Port Deposit on Uie Susque- 
hanna, and similarly along the lower part of the Delaware river from 
Wilmington to Trenton coincidea nearly with the division between the 
hilly Piedmont region on the northwest, consisting of highly tilted 
