68 Scientific Intelligence. 
10. Studies in Spectrum gash alysis 5 3 by J. Norman Lockyer, 
F.R.S. 258 pp. 8vo. New York (D. Appleton & Co. —Interna- 
tional Scientific Series). ss eeotonick Lockyer’s name has been so 
graphy, the spectra of salts, dissociation, quantitative pr nae 
analysis, results of .the study of the sun with the spectroscope, 
and other kindred subjects. The work is a collection of interest- 
ing essays written in a clear and simple style, with excellent illus- 
trations, and embodying what is newest in this branch of science. 
Taken together, however, the subjects are somewhat wanting in 
connection, 
II. GroLogy anp MINERALOGY. 
On Terrace Levels in Pennsylvania ; by Prof. J. P. Lester, 
esr of the Pennsylvania Geological Survey. Letter to J. D. 
ne dated Philadelphia, May 27, 1878.—In my preface to Prof. 
C. White’s Report of Progress’ Q on Alleghany, Butler ae 
foc Counties lying on the north side of Ohio river, in West 
Pennsylvania, I have ventured to discuss the character of the nie 
place a provisional Prot White, of the facts, thus far collected by Prof. 
Stevenson and Pr 
other gentlemen, gence in a study of our surface deposits in 
Ww it 
other districts of the hat opinions I ventu 
much hesitation to ieee were not entirely eet of by 
rof. Stevenson and Prof. ae who had the best right in the 
d. 
¢ 
blocks, confined geogra phically to the country west of the Beaver 
River and north of the he Ohio; and I concluded that a submergence 
to that extent was pro robable ; also, that the upper clay terraces 
represent the sloping plains oF mind which during that submer- 
gence were deposited in the valleys, by ordinary deposit from the 
vesbarriongs - intervening coal-measure high lands. I have (it 
is needless to say) always considered our whole Soil penipihiaad 
sculpture het accomplished and finished previous to the com- 
