1883.] Review of Report C, 2d Geol. Surv. of Penna. 1027 
would have been spent in Chester and the adjoining parts of 
Delaware and Montgomery counties before he would have 
felt ready to write their geology. Owing to the termination of 
his connection with the Second Geological Survey, and the con- 
sequent imperative demands upon his time of other occupations, 
such notes as he had made, which would otherwise have been 
ready in the early summer of 1881, were finished and sent to 
the Geological Survey in Feb. 1882, with the request that he be 
allowed to correct the proof; yet the first impressions seen by him 
were the stereotype or plate proofs of pp. 145 to 354 (without 
the illustrations), These were not received till the present year. 
In the meantime Mr. Hall’s Report C, had appeared,’ and Pro- 
fessor Lesley had stated in the introduction that we could now 
“accept the Palzozoic age of the Philadelphia rocks with a mod- 
erately reserved confidence.” This led to a paper on the horizon 
of the South Valley Hill rocks, before referred to, which was 
honored by favorable comment from a number of distinguished 
geologists, among whom was Professor Lesley himself? 
It is very much to be regretted that the generally valuable and 
justly admired volumes of the Second Geological Survey of Penn- 
sylvania should be accompanied by abook of this kind. Not only 
can the text serve no useful purpose, except to indicate some dry 
facts obscured by a great deal of very unsound reasoning, but it can- 
not conceal by any amount of rhetoric the palpable fact that it 
is amake-shift, consisting of heterogeneous materials in juxtaposi- 
tion but not joined together. The colored map, which repre- 
sents a great deal of hard work, is defaced by a belt which has no 
existence in fact, as the writer well knows, for he sketched it 
as a working hypothesis and completely refuted it afterwards. 
It is hardly unfair to say that if there were a museum for the 
Preservation of teratological specimens of geological literature, 
this volume C, would be more fitly placed there than on the 
Shelves with the best of its alphabetical sisters of the Second 
Geological Survey of Pennsylvania. 
1 October 24, 1882. 
* Professor Lesley said in his remarks on the conclusion of the reading of the 
Paper, that the subject therein treated had been constantly in his mind for many 
months, and he had come to the conclusion that the views just presented were the 
only safe ones to hold, 
