Articles

Following the somewhat bleak picture painted in the consideration of the bacterial diseases of hatchery fish in the last number of The Progressive Fish Culturist, it is a relief to turn to another large group of fish diseases caused by small, single-celled parasitic animals known as the protozoa. To the hatcheryman, the protozoan diseases of fish are just as important as the bacterial diseases for

No abstract available. 

There appears to be surprisingly little definite information on the viscosity of lavas. With few exceptions writers content themselves with such general and indefinite terms as “mobile”, “viscous”, or “highly viscous”. Apparently the only attempts to actually calculate viscosity have been made on Hawaiian lavas. G. F. Beoker (Some queries on rook differentiation, Amer. J. Sci., 4th ser., v. 3, pp.

The feldspathic rock with which the titanium deposits of Virginia are associated appears to be an anorthosite, although the plagioclase is somewhat more sodic than in normal anorthosites. That is, this rock shows evidence of having been introduced as a mush‐like mass of crystals and intersititial magma, and of undergoing very thorough crushing during introduction. This rook was later very thorough

In recent years the Water Resources Branch of the United States Geological Surrey has given considerable attention to the relation of ground‐water to stream‐flow. One locality in which this relation is being studied is about 13 miles from Washington, near Colesvllle, Maryland, where a Kinnison float‐gage is being maintained in a well In connection with the operation of a gaging‐station on the Nort

A survey of the ground‐water resources of the region in which Houston and Galveston are situated was started in December 1930 by the United States Geological Survey in cooperation with the Texas Board of Water Engineers. In connection with this survey a special study is being made of the geochemical relations of the ground‐waters of an area about 25 miles wide and 90 miles long, extending from Gal

Students of Igneous phenomena have long since become familiar with the occurrence of rare minerals in pegmatitic bodies. The great local concentration of rare elements in pegmatite minerals provides a remarkably good opportunity for the Investigation of deep-seated rock constituents, for it is reasonable to suppose that these same elements are widely distributed in minute amounts through the paren

The by‐laws adopted at the meeting of the Section of Hydrology in 1933 provided that the membership of research committees should be reconstituted every three years. There have, accordingly, been some changes in the membership of the Committee on Underground‐Water. Certain members have retired because of pressure of other duties or because they are no longer actively engaged in ground‐water work.

The water in artesian aquifers is confined under pressure. Under ideal conditions in a perfectly rigid artesian reservoir a change of pressure in one part of the reservoir should produce a corresponding change of pressure in all other parts of the reservoir. Theoretically, the transmission of pressure should take place rapidly and without any movement of water other than the small amount resulting

Snow‐fields and the so‐called névés of glaciers on lofty mountains often present a peculiar, honeycombed appearance, the surface being pitted with deep cell‐like hollows a foot or two feet in diameter and from a few inches to several feet in depth. When typically developed these hollows are closely spaced, the divides between them consisting merely of attenuated blades and pinnacles of hard, granu

In the paper entitled “The measurement of the permeability of porous media for homogeneous fluids” by R. D. Wyckoff and others [42] a unit of permeability is proposed which is based on centimeters, seconds, and atmospheres of pressure (76 centimeters of mercury).In 1923, when the Hydrologic Laboratory of the United States Geological Survey was organized, much study was given to the question of a c

The personnel of this Committee during the past year, practically the same as during the previous year, has been as follows: C. S. Howard, Chairman—United States Geological Survey, Washington, D.C. L. C. Case—Gypsy Oil Company, Tulsa, Oklahoma. W. D. Collins—United States Geological Survey, Washington, D.C. H. F. Flynn—United States Engineer Office, 35 South Ninth Street, Philadelphia, Pennsylvani