b42 The American Geologist. May, 1892 
adjoining states, with the entire system of the Canadian Pacific railway, 
and its connections from Port Arthur to the Pacific. Series of altitudes 
along the course of the principal rivers are also arranged separately 
in tabular form, including the lowest and highest stages of the Missis- 
sippiand Missouri rivers, during many years at stations along all their 
course, as determined by the Mississippi and Missouri River Commis- 
sions. The basis of reference throughout is the mean sea level. 
The Viscosity of Solids. By Cart Barus. pp. 139; with6 plates, 
and 28 figures in the text. (Bulletin No. 73, U. S. Geol. Survey, 1891. 
Price 15 cents) This treatise is a contribution toward the solution of 
questions bearing on the viscosity of rock masses, following a general 
plan devised by Mr. Clarence King. The experimental investigation of 
the viscosity of steel leads the author to believe that he has discovered 
a reliable working hypothesis substantially corroborative of Maxwell’s 
theory on this subject. 
The Minerals of North Carolina. By FRreperick A. GENTH. pp. 
119. (Bulletin No. 74, U. S. Geol. Survey, 1891. Price, 15 cents.) Since 
the publication of the latest previous catalogue of the minerals of this 
state in 1881, there has been great activity in the development of its 
mining: and by the reopening of old localities and the discovery of new 
deposits, a considerable number of species have been added. The 
author states that “ minerals formerly supposed to be rare are now found 
abundantly, and through the recent developments of chemical industry 
even such unusual species as samarskite, mouazite and zircon have 
acquired commercial importance. For example, in response to an in- 
dustrial demand, North Carolina has supplied zircon and monazite by 
the ton, and samarskite by the hundred weight; and the output can be 
increased almost indefinitely.”” Many new analyses are presented in 
this memoir. 
Record of North American Geology for 1887 to 1889, inclusive By 
Nexson Horatio Darton. pp. 173. (Bulletin No. 75, U. 8S. Geol. 
Survey, 1891. Price 15 cents.) The scope of this record includes Geo- 
logic publications printed in North America, and publications relating 
to North American geology wherever printed. The entries, which are 
all arranged in a single alphabetic sequence, comprise authors’ names, 
with full titles of separate papers and concise descriptive notes of their 
contents ; titles of journals, state and national government reports, etc., 
under which authors and short titles of the contained papers are given ; 
and subject references, which are geographic, stratigraphic, and mis- 
cellaneous. 
A Dictionary of Altitudes in the United States. ( second edition ). Com- 
piled by Henry Gannerr, Chief Topographer. pp. 393. (Bulletin No. 76, 
U.S. Geol. Survey, 1891. Price, 25 cents.) This work contains consider- 
ably more extensive data than its earlier edition, which was published in 
1884; the additions being mainly altitudes determined by railroad sur- 
veys. Itis also more convenient for reference, as all the points noted 
