1883.) Review of Report G, 2d Geol, Surv. of Penna. 1025 
the south-west part of Chester county with a somewhat indefinite 
line,” &c., &c. 
It may not be entirely inapposite here to advert to the sin- 
gular discrepancy between the principles and practice of one who 
but a little while ago plead so eloquently in the “Iron Manufac- 
turer's Guide” and in “Coal and its Topography” for the rights 
of the subordinate geologist.) 
In a great mass of description, taken bodily out of Professor 
Rogers’s work, there is found evena description of a few lines given 
to Wood’s chrome mine iz Lancaster county, made in 1853/ not- 
withstanding that this mine is treated quite fully as it exists to- 
day in Vol. Cs on pp. 177, 192, 193, 194, 195 and 196, and speci- 
mens from it are recorded on pp. 286 and 287 of that volume. 
A striking instance of the manner in which this volume is 
edited is exhibited on the page plate opposite p. 98, called 
“Three hypotheses of structure.” 
The upper (Fig. 1) is called “Theory of H. D. Rogers,” the 
lower (or Fig. 3) is entitled “Theory of C. E. Hall,” while the 
middle (Fig. 2) designed to embody the fault along the South 
Valley hill, is unmarked by the name of an author, though this is 
the view defended by Frazer, and letters have been received by 
the latter from many eminent geologists of the United States and 
ada expressing their accord with it. The pre-Potsdam age of 
the South Valley Hill rocks was also strongly endorsed by Pro- 
fessors Gosselet and Barrois, who examined with great minuteness 
the theories of the geology of this region put forth in the Mémoire 
before alluded to. 
A great deal of what has been objected to above may be con- 
ceded to the editor of C, because of the latter's own difference of 
` Opinion from that of Dr. Frazer, but this is not the case with all. 
1 In the preface to the “ Iron Manufacturer’s Guide,” 1859, p.9, Professor Lesley 
‘Says: ‘One must take the names as and where they are published, whatever may 
be the unknown wrong done to the real workers and thinkers.” Again, p. 668, in 
referring toa mistake made by Professor H. D. Rogers, he says: “ His work g full 
of such blunders, the discredit of which would have been saved him had he given 
ge credit to his various authorities whenever it was a or paa republished 
ir own reports i ; anguage, as he should have done. 
Tn the « nage go its Tomana ” (a charming little book now un- 
fortunately out of print) Professor Lesley says (p. 210) : “ No primary report should 
receive the touch of any hand but that of the first observer. Let it come fresh and 
o 
_ Clean before the examination of the world, and stand or fall (with its author) by its 
wn merits,” 
