Progress in the Analysis of Cosmic-Ray Observations

The report herein contained is of a preliminary character, and is intended to exhibit only the first steps of the problem in hand. At the Des Moines meeting of the American Physical Society on Dec. 31 last, the writer presented a paper in which were set forth details of a method of treating the observations of Millikan and Cameron upon the absorption of the cosmic-rays, in order to render them susceptible to adjustment by the method of least squares

A New Method of Identifying Polarized Light Reflected from Small Opaque Crystals.

The method is a modification of one used originally by Voigt for the identification of elliptically polarized light. The light under examination passes first through an arrangement of quartz wedges acting as a Babinet compensator, then through a rotator consisting of another pair of quartz wedges cut perpendicular to the axis, one from right-handed, the other from left-handed quartz; and finally through a large Nicol prism. The result is that the field is filled with rows of black spots in regular arrangement; and from the location of these spots with reference to the cross-hairs, as photographed, the exact character of the elliptic vibration can be readily calculated

A Simplified Deduction of Maxwell\u27s Distribution Law

It is the object of this paper, not to contribute to the volume of evidence for the validity of Maxwell\u27s molecular velocity law, or to improve upon the cogency of the various lines of argument which have previously led to it; but rather to bring the deduction within easy reach of any student of integral calculus who has knowledge of the merest rudiments of the theory of errors

On the Existence of a Minimum Volume in Solution

This research has for its general object to inquire into the physical condition of substances in near-saturated aqueous solution. The subject was attacked by means of experiments at different temperatures on the apparent specific volume in solution; by which is meant, the volume of that amount of solution which contains one gram of the solute, minus the natural volume of the water contained therein. This quantity is always somewhat less than the volume of the solid solute

Calibration of a Gold Leaf Electrometer for Ionization Work

The ordinary type of ionization electroscope having a straight, horizontal scale of 100 divisions in the focal plane of its microscope, over which the image of the gold leaf is seen to move obliquely, is subject to well-marked variations which, for certain kinds of work, necessitate its calibration

Test of a U-Tube Capillary Viscometer

The usual form of Poiseuille\u27s equation for the flow of a viscous liquid through a capillary tube is not difficult to deduce mathematically upon the basis of certain assumptions. These are: (1) that there is no appreciable slip at the inner surface of the capillary, that is, that at this distance from the axis the speed of flow is zero; (2) that the flow is steady, so that inertia plays no part in it; (3) that the capillary is perfectly cylindrical and perfectly straight, and (4) that there are no end effects, such as surface tension and eddies

The Address of the President - Atomicity in Physical Nature

Atomicity in Physical Nature-From the earliest times men have been curious about the makeup of material things and the mechanism of visible processes. When Empedocles reasoned that all change is merely a rearrangement of permanent, unchangeable parts - an idea which the YAtomists and Anaxagoras later elaborated in greater detail - he merely gave expression to what seems to be an intuitive conviction about Nature in general. Anaxagoras recognized the existence of atoms and the fact that there are different kinds of atoms; and he furthermore introduced the grotesque idea of atoms endowed with intelligence, by way of accounting for the order existing in Nature