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Thermoelectric Effect In Single Crystal Zinc Wires, E. G. Linder Jan 1926

Thermoelectric Effect In Single Crystal Zinc Wires, E. G. Linder

Proceedings of the Iowa Academy of Science

The work reported is a continuation of measurements published in the Physical Review for October, 1925. The thermol e.m.f. of the zinc crystals against copper has been measured from -182°C to 480°C for crystals having orientations from about 10° to 90°. The relation between thermoelectric power and temperature is definitely not linear, but may he represented fairly well by a second degree equation. The nature of the effect in the neighborhood of the melting point will be discussed.

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A Modification Of Lees' Method For The Determination Of The Heat Conductivity Of A Poor Heat Conductor, Paul C. Oversheet Jan 1926

A Modification Of Lees' Method For The Determination Of The Heat Conductivity Of A Poor Heat Conductor, Paul C. Oversheet

Proceedings of the Iowa Academy of Science

Lees' Method is described at length in the Phil. Trons. An 1898, vol. 191, also in a general way in Poynting and Thompson's "Heat" and Watson's "Textbook of Physics." The modified method is described in detail in "The Measurement of the Heat Conductivity of Sulfur and a Sulfur-Coke Mixture," Physics Thesis by Paul C. Overstreet, State University of Iowa, 1925. This method consists of the measuring of the temperatures of a hot copper disk, U, on one side of a poor heat conducting disk, S, and that of a cooler disk, M, on the other side of S, after …

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Optical Constants Of Bismuth Crystals In The Ultra-Violet, Florence E. Dix Jan 1926

Optical Constants Of Bismuth Crystals In The Ultra-Violet, Florence E. Dix

Proceedings of the Iowa Academy of Science

Index of refraction and extinction index for light reflected from a cleavage surface of a bismuth crystal have been determined at several wavelengths in the ultra-violet. The crystelliptometer of Weld is being used. A comparison in the overlapping region with the measurements of Rowse will be given.

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The Iowa State College Reasoning Test, Thomas F. Vance Jan 1926

The Iowa State College Reasoning Test, Thomas F. Vance

Proceedings of the Iowa Academy of Science

In order to arrive at the point of this paper on the subject, "The Iowa State College Reasoning Test" it is necessary to describe briefly the other tests of which it is one in the series. The psychological test which has been given this year to the Freshman class of Iowa State College is a modified Alpha. The Alpha was chosen as a basis on which to construct a new form for the reason that it has given consistently higher correlations than it has been possible to secure with any other test. In the modified form, Arithmetic, the Synonym and …

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A Preliminary Study Of The Nature Of Finality In Melody, Ruth Updegraff Jan 1926

A Preliminary Study Of The Nature Of Finality In Melody, Ruth Updegraff

Proceedings of the Iowa Academy of Science

According to a recognized definition, a melody is a succession of musical sounds which is felt to constitute a unity. The stipulation, sometimes made, that this unity must be aesthetic, is felt to be not only ambiguous, the aesthetic depending to some degree on individual taste, but restricting, in the sense that melodies termed aesthetic by common consent would be few in number. Unity implies, first, an interrelationship, and secondly, coherence and completeness as a whole; that is, relationship and finality. The melody problem is that of discovering how a series of tonal stimuli can excite a feeling of unity.

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Notes Of Oxygen Consumption In Turtles Chrysmus Marginata Belli And Chelydra Serpentina Linn, Francis Marsh Baldwin Jan 1926

Notes Of Oxygen Consumption In Turtles Chrysmus Marginata Belli And Chelydra Serpentina Linn, Francis Marsh Baldwin

Proceedings of the Iowa Academy of Science

In an earlier paper read before the Academy, data were given on the comparative ratio of oxygen consumption in certain fishes and other marine forms. These figures were obtained by analysis of samples of water in which the animals had been kept, using the chemical method devised by Winkler. As is customary in such work, the figures of consumption were reduced to the volumetric basis at uniform pressure and temperature and were expressed in cubic centimeters per gram of body weight per hour. There resulted from these studies an interesting comparison in metabolic rate in the different fishes, being greatest …

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The Solar Surface During The Past Five Years A Review Of Sunspot Observations Made At Alta Iowa From 1921 To 1925, David E. Hadden Jan 1926

The Solar Surface During The Past Five Years A Review Of Sunspot Observations Made At Alta Iowa From 1921 To 1925, David E. Hadden

Proceedings of the Iowa Academy of Science

Observations of the solar surface were commenced by the writer in August, 1890, and brief reviews have been published in these Proceedings from time to time, the first being in Volume X, 1902, and succeeding ones in Volume XV, 1908, and Volume XXVIII, 1921, the present paper brings the series down to the close of the year 1925, covering a period of over 35 years and embracing four minimum and three maximum epochs of the 11½ year cycles of solar changes. All of the five years' observations were made with a 5½-inch refracting telescope, equatorially mounted, being the same instrument …

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Notes On The Reversal Of The Sodium Line, L. B. Spinney Jan 1926

Notes On The Reversal Of The Sodium Line, L. B. Spinney

Proceedings of the Iowa Academy of Science

The reversal of the sodium line may be demonstrated without the use of a slit or a spectroscope. An incandescent lamp having either a carbon or tungsten filament is placed immediately behind a good sodium flame and viewed from a distance of fifteen or twenty inches through a diffraction grating. The first- and second- order spectra, right and left, will both be in view and in the orange-yellow region of each will appear a sharp dark-line image of the filament of the lamp. This image constitutes the dark-line spectrum of the sodium vapor.

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The Absorption Of Moisture By Hard Rubber, Geo. E. Thompson Jan 1926

The Absorption Of Moisture By Hard Rubber, Geo. E. Thompson

Proceedings of the Iowa Academy of Science

A study is being made of the effects of relative humidity and electric fields on moisture absorption by hard rubber. A specimen of hard rubber is suspended in a constant temperature box from the beam of a sensitive chainomatic balance. The relative humidity of the box is varied by placing sulphuric acid of various concentrations in the box. The rubber specimen is suspended between two brass electrodes which are attached to a 10,000 volt transformer. At 100 per cent humidity the effect of the electric field is to increase the rate of moisture absorption at first and later to diminish …

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The Theory Of The Two-Way Quincke Tube, G. W. Stewart Jan 1926

The Theory Of The Two-Way Quincke Tube, G. W. Stewart

Proceedings of the Iowa Academy of Science

The long known Quincke two-way tube has been assumed to eliminate transmission by interference only at a frequency corresponding to a difference of path of one-half wave length. The author has derived the theory of the action and finds that the ratio of transmitted to incident energy.

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A New Analysis Of The Action Of Amsler's Polar Planimeter, George E. Davis Jan 1926

A New Analysis Of The Action Of Amsler's Polar Planimeter, George E. Davis

Proceedings of the Iowa Academy of Science

The theory of Amsler's polar planimeter, as commonly given, leads to the expression A= L h, where A is the area circumscribed, L is the length of the tracer arm, and h is the net distance of translation of the tracer arm in a direction perpendicular to its length. However, it can be shown that the area may also be given by A = L 2 ∅, where ∅ is the net angle through which the tracer arm has rotated about either of its ends. But as the tracer point passes around the area A, the tracer arm does …

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The Dielectric Properties Of Some Crystals At Radio Frequencies, A. A. Aardal Jan 1926

The Dielectric Properties Of Some Crystals At Radio Frequencies, A. A. Aardal

Proceedings of the Iowa Academy of Science

An attempt has been made to study the dielectric properties of a few crystals at radio frequencies ranging between 50 and 3000 kilo-cycles per second. The properties studied are phase difference, dielectric constant, capacity, resistance, and power factor. It is found that the dielectric constant, the electrical capacity and resistance decreases with the increase in frequencies of electrical oscillation, and that the phase difference and power factor increase with increase in frequencies.

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The Phosphorescence Of Fused Quartz, A. C. Bailey Jan 1926

The Phosphorescence Of Fused Quartz, A. C. Bailey

Proceedings of the Iowa Academy of Science

Experiments performed here corroborate the report of Drummond and Webster that fused quartz can be activated to phosphorescence by being irradiated with ultra violet light from a quartz mercury vapor lamp. It is also found that the fused quartz is thermoluminescent. The radiations emitted from the phosphorescent and thermoluminescent quartz appear to be confined largely, if not completely, to the visible region. These radiations, however, at ordinary room temperatures, are of such low intensity as to be invisible to the eye.

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Fifty Years At The Teachers College, David Sands Wright Jan 1926

Fifty Years At The Teachers College, David Sands Wright

Iowa Book Gallery

A history of the Iowa State Teachers College, later known as the University of Northern Iowa.

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Table Of Contents Jan 1926

Table Of Contents

Proceedings of the Iowa Academy of Science

No abstract provided.

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In Memoriam: Philip Sprong; Walter Scott Hendrixson; Clyde Leslie Winter Jan 1926

In Memoriam: Philip Sprong; Walter Scott Hendrixson; Clyde Leslie Winter

Proceedings of the Iowa Academy of Science

No abstract provided.

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The Address Of The President - The Ministry Of Science, R. I. Cratty Jan 1926

The Address Of The President - The Ministry Of Science, R. I. Cratty

Proceedings of the Iowa Academy of Science

We are living in a very progressive age - one which when compared with that of our forebears, is filled with advantages for our welfare and enjoyment that challenges the attention of every thoughtful person. That knowledge is power was never a more self-evident truth than it is today, and science, which is simply classified knowledge, is every day coming more closely in touch with human lives, and ministers to us in innumerable ways undreamed of a century ago. Just how great our debt is for all this it is difficult to say. Captain Roald Amundson, that modern Viking whom …

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The Transference Numbers And The Degree Of Solvation Of The Ions Of Lithium Chloride In Certain Alcohols, J. N. Pearce, W. G. Eversole Jan 1926

The Transference Numbers And The Degree Of Solvation Of The Ions Of Lithium Chloride In Certain Alcohols, J. N. Pearce, W. G. Eversole

Proceedings of the Iowa Academy of Science

The low migration velocities of some of the ions of the elements of low atomic weight, as well as the many other phenomena that are not explained by simple electrolytic dissociation, have led to the belief that the ion does not lead an independent existence in the solution, but is solvated, or combined chemically with one or more molecules of the solvent.

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Relativistic Reflections, Edward S. Allen Jan 1926

Relativistic Reflections, Edward S. Allen

Proceedings of the Iowa Academy of Science

An important result of the great interest in the theory of relativity has been that mathematicians and physicists on the one hand, philosophers on the other, have given increasing attention to each other's work. It may not, then, be out of place for one whose interest in the subject has been mainly on the mathematical side to examine some philosophical inferences which have been drawn from it.

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Further Evidence Of The Effect Of Valence And Chemical Combination On The K Limit Of Sulphur, R. A. Rogers Jan 1926

Further Evidence Of The Effect Of Valence And Chemical Combination On The K Limit Of Sulphur, R. A. Rogers

Proceedings of the Iowa Academy of Science

A number of spectrograms have been obtained showing the K absorption limit of sulphur. The absorption was due to sulphur in the gypsum (Ca SO4. 2H2O) crystal used in the analysis of the M series absorption spectra of the platinum group.

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A New Type Of Photoelectric Colorimeter, D. H. Palmer, Jay W. Woodrow Jan 1926

A New Type Of Photoelectric Colorimeter, D. H. Palmer, Jay W. Woodrow

Proceedings of the Iowa Academy of Science

A photoelectric colorimeter has been constructed which is capable of detecting small changes in the color of meat. With this apparatus it was possible to measure the variation in the color of meat as a function of the time of exposure to the air. The effects of temperature upon the color variation were also measured; and some data has been obtained showing the relation between the color and the grade of the meat.

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The Moulding Action Of Surface Tension On A Free Sheet Of Water, L. B. Spinney Jan 1926

The Moulding Action Of Surface Tension On A Free Sheet Of Water, L. B. Spinney

Proceedings of the Iowa Academy of Science

A smooth stream of water falling vertically is allowed to strike the center of a small circular plate placed horizontally. The water under these circumstances spreads laterally over the edge of the plate in a thin stream. Under the action of gravity and surface tension this thin bubble-like stream assumes various forms determined by the velocity of the stream impinging upon the plate and the dimensions of the various parts of the apparatus. The bubble may be made to assume a more or less nearly spherical form or, by joining a free water surface below, to shape itself into the …

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The Toxic Effect Of Ultra Violet Radiations Upon Yeast And Yeast-Growing Media, A. C. Bailey Jan 1926

The Toxic Effect Of Ultra Violet Radiations Upon Yeast And Yeast-Growing Media, A. C. Bailey

Proceedings of the Iowa Academy of Science

We have not found in our work any region of ultra violet energy which will produce a stimulation of yeast growth in any synthetic medium used. In every case the action of the ultra violet radiations has produced a toxicity in the media in proportion to the amount of ultra violet received. Even fifteen minutes of ultra violet light at 16 cm. from the lamp produced such a toxicity in the medium that the yeast count twenty-four hours afterwards was ten per cent below the control count.

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A Vacuum Tube Tester For Routine Work Using Alternating Current, P. S. Helmick Jan 1926

A Vacuum Tube Tester For Routine Work Using Alternating Current, P. S. Helmick

Proceedings of the Iowa Academy of Science

Some form of vacuum tube tester is a necessity in every radio laboratory. The vacuum tube tester herewith described is the result of an effort to design a simple instrument suitable for routine work, and which could be left permanently connected to the lighting circuit thus being always ready for use.

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Magnetic Properties Of Thin Films Of Iron, Electrolytically Deposited, E. P. T. Tyndall Jan 1926

Magnetic Properties Of Thin Films Of Iron, Electrolytically Deposited, E. P. T. Tyndall

Proceedings of the Iowa Academy of Science

Films of iron from 100 to 200 millimicrons thick deposited electrolytically from neutral and acid solutions of iron ammonium sulphate show a surprising magnetic hardness. At a field of 40 gauss the intensity of magnetization is from 200 to 300 c.g.s. units. No sudden increase in magnetization is found up to fields of 150 gauss. Films deposited on the initial film, using much smaller current densities than that required for the initial deposit, show the usual properties of electrolytic iron. An intensity of magnetization of 1000 is reached at 40 gauss field. The cause of the hardness of the initia1 …

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Potentials Of Spark Lines Of Mercury Vapor, J. A. Eldridge Jan 1926

Potentials Of Spark Lines Of Mercury Vapor, J. A. Eldridge

Proceedings of the Iowa Academy of Science

It has been shown by a series of photometric readings on thirty spark lines of mercury falling in the range 2000-5000 angstroms, that these lines fall into three groups. (1) Excitation potential at about 20 volts, (2) excitation potential about 28 volts and (3) excitation potential about 55 volts. The exact values of these potentials are uncertain since they depend upon pressure and current conditions. If we accept the results of Smythe that double ionization occurs first at 20 volts and triple ionization certainly not under 100 volts we may suppose the first class of lines as due to the …

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A Comparison Of Power Output Conical, Hyperbolic And Exponential Trumpets, G. W. Stewart Jan 1926

A Comparison Of Power Output Conical, Hyperbolic And Exponential Trumpets, G. W. Stewart

Proceedings of the Iowa Academy of Science

These measurements are presented as illustrative of the advances that have been made in the measurement of acoustic power. They refer of course to single cases, but they are of interest in showing the actual fluctuations of both components of impedance and of the power output in the three types of trumpets stated in the title.

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Variation Of The Intensity Of The Spectral Lines Of Mercury With The Velocity Of The Exciting Electrons, W. D. Crozier Jan 1926

Variation Of The Intensity Of The Spectral Lines Of Mercury With The Velocity Of The Exciting Electrons, W. D. Crozier

Proceedings of the Iowa Academy of Science

A study has been made of the variation of the intensity of the spectral lines of mercury when excited by impact of electrons of controlled velocity. In accordance with some earlier observations by Dr. J. A. Eldridge, it is found that the lines divide into two classes. In one class the intensity of the line increases uniformly from zero to a certain limit as the velocity of the electrons increases above the minimum exciting velocity. In the other class the intensity rises rapidly to a maximum at a velocity not far above the minimum exciting velocity, and then decreases to …

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Electricity And Mechanics, John A. Eldridge Jan 1926

Electricity And Mechanics, John A. Eldridge

Proceedings of the Iowa Academy of Science

When electric charges are in motion the forces between them differ from the electrostatic forces. The magnetic concept is used to take account of these non-electrostatic forces. The magnetic effect of a moving charge is relative to the electrostatic extremely small except when the velocity approaches that of light. However due to the circumstance that the electrostatic effects often, as in a wire carrying a current, practically cancel, the magnetic forces are very important. According to our present beliefs any field of force changes in an analogous manner if it be moved. There is theoretically the same excuse for speaking …

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The Scattering Of X-Rays By Camphor, Roger M. Morrow Jan 1926

The Scattering Of X-Rays By Camphor, Roger M. Morrow

Proceedings of the Iowa Academy of Science

The ionization chamber method of analysis was used. A Soller slit placed between the scattering material and the x-ray tube, gives a wide beam of nearly parallel rays; one placed between the scattering material and the ionization chamber limits the angle of divergence of the rays and yet permits a wide beam to enter the ionization chamber. Thus a large sample of material could be used thereby increasing the intensity without any sacrifice of resolving power.

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