270 TJic American Geologist. April, 1904. 
eralogy in University College, London. In 1853 he accepted 
the new chair of mineralogy and geology in University College, 
Toronto, a position which he held until 1896 when he returned 
to England, having inherited an estate. 
UNITED STATES GEOLOGICAL SURVEY. 
Collection of fossil plants from the Yukon coal areas of 
Alaska made in 1902 by Arthur J. Collier and in 1903 by Ar- 
thur Hollick have been examined by F. H. Knowlton, who, in 
a preliminary report, state's that these fossils are of both Terti- 
ary and Cretaceous age. This find of Cretaceous fossils in some 
of the coal bearing rocks of Alaska is an important and inter- 
esting discovery. At present it seems that the coal on the Yu- 
kon above Ramport is of Tertiary age, while that below Ram- 
port is Cretaceous. 
Recent experiments by Heinrich Ries on the effect of tannin 
in clays are of importance. The experiments proved conclusive- 
ly that the addition of either tannin or straw emulsion to the 
clay diminishes the amount of water necessary for tempering 
the clay ; that it causes a decrease in the air shrinkage, as there 
is less water to evaporate from the clay ; that the total shrink- 
age after burning is consequently less in most cases ; that the 
increase in the tensile strength of the clay is very remarkable; 
that the air cracking is greatly diminished, even in the worst 
clays ; that the hardness of the treated clay, both in the green 
condition and in the burned material, is such that it is capable 
of scratching the untreated clay ; and that the plastic feeling of 
the clays tested is greatly enhanced. 
The Tola (Kansas) quadrangle is among the topographic 
maps recently issued. 
The only expedition which has crossed central Alaska from 
the Yukon to the Arctic ocean was undertaken by F. C. Schra- 
der and W. J. Peters in 1901. An account of this expedition 
will soon be published as Professional Paper No. 20, under the 
title of '^A reconnaissance in northern Alaska." 
Among the folios of the Geologic Atlas recently issued are 
the following: Indiana (Pennsylvania), No. 102; Nampa 
(Idaho), No. 103; Silver City (Idaho), No. 104. 
The results of topographic work in Texas in the region of the 
big bend of the Rio Grande are shown on the following quad- 
rangles: Polvo, Terlingua, Terlingua Special, Chiso, and an 
unnamed quadrangle. The first three are ready for distribution. 
The district covered by these maps is of interest because of the 
Terlingua quicksilver deposits, recent finds of cinnabar, marked 
box canyons and peculiar topographic features. 
