摘要:

Reviewing an article on “Uniformity in Aerographic Notation,” Sir Napier Shaw calls attention to the common usage of the capital letters N.E.S.W. for wind directions, and the established usage in Physics of N for Avogadro's constant, E for Energy, S for Entropy and W for internal work.The criticism is constructive and suggestive. The question arises: Is it not desirable to follow the lead of navigator and magnetician and use degrees instead of letters to indicate direction of air flow? There are some distinct gains from such a usage for the aerographer or chart maker of the winds. Official weather bureaus record direction on a 45‐degree basis; that is, eight directions are given. It has long been felt that such records were not sufficiently detailed. Precision, detail and convenience are gained by the use of the d

ISSN:0002-8606    

DOI:10.1029/TR002i001p00050

年代:1921

数据来源: WILEY

摘要:

A brief historical statement was made with reference to the measurement of the horizontal intensity of the earth's magnetic field by electrical methods, and a general description of sine and tangent galvanometers was given, with the suggestion of an improvement in the latter. Then followed a detailed description of a new sine galvanometer, constructed, with certain exceptions mentioned below, in the workshop of the Department of Terrestrial Magnetism.The base of the instrument, including the tripod, circles, etc, was taken from one of Wild's theodolites, constructed by Edelmann, and was much improved by the substitution of non‐magnetic parts for parts too magnetic, and by the substitution of electrical illumination of the precision circle for daylight illumination by mirror

ISSN:0002-8606    

DOI:10.1029/TR002i001p00054

年代:1921

数据来源: WILEY

摘要:

At the meeting of the International Commission for Terrestrial Magnetism held at Innsbruck in 1905 a resolution was adopted recommending that magnetic observatories classify each day according to its magnetic character as quiet, moderately disturbed, or severely disturbed, using the notation 0, 1, and 2 for this purpose. This recommendation has been adopted by different observatories, one after another, so that now nearly all of the prominent observatories are sending quarterly reports of the magnetic character of days to the Netherlands Meteorological Institute and that institution is publishing them, thus making the data available for all. While this method of characterization is necessarily rough and influenced by the personal equation of the observer, yet the mean of a large number of estimations (between 35 and 40 at the present time) gives a very good idea of the relative magnetic condition of the whole earth from day to day. It does not, however, give an absolute measure of the daily fluctuations of the earth's magnetism nor does it permit a comparison of conditions in different parts of the earth.

ISSN:0002-8606    

DOI:10.1029/TR002i001p00055

年代:1921

数据来源: WILEY

摘要:

When attempting to find correlations between manifestations of the sun's activity and those of the earth's magnetic and electric activity, three points require immediate consideration:(1) What shall be taken as an adequate measure of the sun's activity with respect to such radiations and emanations as are likely to have an effect upon the magnetic and electric fields of the earth?(2) What shall be taken as an adequate measure of the earth's magnetic activity, or of the earth's electric activity?(3) What quantities shall be taken as defining the so‐called normal or undisturbed condition of the earth's magnetic field, or of the earth's electric fiel

ISSN:0002-8606    

DOI:10.1029/TR002i001p00059

年代:1921

数据来源: WILEY

摘要:

The paper was devoted largely to a description of certain investigations on the penetrating radiation in progress at the University of Minnesota, under the author's direction. It opened with a brief review of the status of our knowledge with regard to the penetrating radiation.In a hermetically sealed zinc vessel freed from radioactive air, ions are produced at a rate of about 8 or 9 per c.c. per second over the land. According to the computations of A. S. Eve, the normal gamma‐ray radiation from the atmosphere is capable of accounting for about 0.06 ion per c.c. per second, while that from the soil will account for 1.6 ion per c.c. per second, making in all 1.7 ions. On account of the secondary ionization resulting from electrons emitted from the walls of the vessel by the primary radiation, this value becomes increased to about 2.5 ions in the case of vessels of the size ordinarily used. If this value be subtracted from the 8.5 ions per c.c. per second found over land, there remains about 6 ions per c.c. per second attributable to causes which are not directly obvious, and this corresponds roughly to the ionization (4 to 6 ions per c.c. per second) observed over the ocea

ISSN:0002-8606    

DOI:10.1029/TR002i001p00065

年代:1921

数据来源: WILEY

摘要:

The Department of Terrestrial Magnetism, in accordance with its director's plans, has for many years been making not only magnetic but also atmospheric‐electric observations aboard its survey vessel, theCarnegie. It is thus contributing the chief data for mapping both the earth's magnetic field and its electric field. Furthermore, since 1915 numerous observations have been made aboard theCarnegieto determine the nature and magnitude of the changes in the electric condition of the atmosphere which take place during a 24‐hour cycle.For thepotential‐gradientthe general procedure in the diurnal‐variation observations is to make a set of 20 observations during each of 24 consecutive hours. The observations for such a set require about 20 minutes and their mean value is referred to the mean time for the set. From deductions based on the observations made prior to April, 1916, it appeared that the diurnal variation of the potential‐gradient over the oceans probably did not differ much from that which has been found at many land stations; that is, they indicated two rather pronounced maxima and two minima during a 24‐hour period. However, very few data were available from oceans other than the Pacific, and as pointed out in the report just cited, a large percentage was derived from series of observations which were terminated by the advent of unfavorable weather. It should also be noted in passing that Swann a year later in discussing the results of the observations for the year ending February 20, 1917, states that “the effect of the 12‐hour Fourier wave is less important in the present curves than in those alr

ISSN:0002-8606    

DOI:10.1029/TR002i001p00073

年代:1921

数据来源: WILEY

摘要:

Investigations of the ocean have generally been carried on by geographers and geologists, oftentimes incidentally to those of other divisions of these extensive fields of science. Accordingly, qualitative methods so characteristic of geography and geology have been widely used in oceanographic investigations. Such qualitative methods and the empirical treatment of quantitative field observations have been very suggestive, have stimulated interest, and led to certain broad generalizations that are essentially correct. However, there has been a tendency toward rather loose reasoning and lack of consideration of established quantitative principles of physics, which has resulted in certain erroneous conclusions.

ISSN:0002-8606    

DOI:10.1029/TR002i001p00078

年代:1921

数据来源: WILEY

摘要:

The modern tendency in physical research is to replace indicating instruments by recording instruments wherever possible. This has been especially true in the science of meteorology where the recent advances have been brought about almost entirely by the remarkable improvements and developments in recording instruments. In the related science of physical oceanography there are practically no recording instruments now in general use, except possibly the tide‐gage. If meteorology has been so greatly benefited by such instruments, surely in oceanography, where the changes in the physical properties are so much more regular and therefore more easily interpreted, great advances should be looked for through the addition or substitution of recording instrument

ISSN:0002-8606    

DOI:10.1029/TR002i001p00082

年代:1921

数据来源: WILEY

摘要:

The ocean of today stands at the end of a succession of oceans that have existed since land and water were first divided from each other on the earth's surface. This fact, admitted by everyone, needs to be emphasized in order to make clear the transcendent importance of the study of marine sediments. It is possible to measure the depth and the temperature of the waters of the present ocean, to sample its waters from the surface to the bottom of its greatest abysses and examine them chemically, and to measure directly or to infer from measurable factors its currents. It is also possible to study the sediments deposited on the floor of the ocean and around its margins. These and other features of the present ocean can be known by direct processes but over a large part of the earth's surface where there was once sea there is now only land, and the depth, temperature, chemical composition, and currents of bodies of waters no longer existent cannot be measured. That seas once extended over regions now land is known through the record made by the sediments and these sediments supply the fundamental data for recognizing the physical features of the vanished oceans.

ISSN:0002-8606    

DOI:10.1029/TR002i001p00085

年代:1921

数据来源: WILEY

摘要:

The intervals between sounding stations must be gauged by the dimensions of the orographical features whose presence it is intended to disclose. Leaving out of consideration details of topography and confining the attention to features of the greatest prominence, inquiry must be made as to the form and dimensions of the slenderest isolated submarine peak that could be raised from the floor of the ocean to a mountainous height and remain standing under the stresses of its own weight and of the superincumbent body of water. For if the spacing of soundings be such as to give indication of the presence of the slenderest form that could stand, then evidence of the presence of any orographical forms that may exist is likely to be afforded. Theoretically, the shape of an isolated submarine peak would be that of a solid of revolution in which the resistance to crushing of any horizontal section is equal to the combined weight of the portion of the formation above that section and of the superincumbent body of water.

ISSN:0002-8606    

DOI:10.1029/TR002i001p00090

年代:1921

数据来源: WILEY