Digital Commons Network^™

Notes On The Production And Some Electrical Properties Of Tellurium Crystals, W. E. Tisdale

Proceedings of the Iowa Academy of Science

This report deals with the production of Tellurium crystals, and the effect of temperature on their electrical properties. An investigation of Tellurium was undertaken primarily to settle the question of its change of resistance with light, or its light sensitiveness. It occurs in the periodic table in the same column with Selenium, and in the same row with antimony, which elements show an effect on light sensitiveness. Adamsin 1876 made some experiments on Tellurium cells and reported ''a distinct though very slight influence of light on their conductivity". Siemens, Knox, and Saunders report that there is no effect of light …

The Absence Of Liberation Or Absorption Of Electrons During A Change From The Conduction To The Non-Conducting State, L. E. Dodd

Proceedings of the Iowa Academy of Science

Metallic selenium in the crystalline form is an electrical conductor. In the amorphous form, which may be produced by melting a selenium crystal, the substance is an electrical insulator. If, as supposed, electrical conductivity in metals is due to free electrons, then in the change from the conducting to the non-conducting state there must be a disappearance of free electrons. This disappearance could be accounted for by a liberation of electrons into the space surrounding the substance, or by a recombination of free electrons with positive residues to form the neutral molecules of the insulator. In this paper is described …

The Crystal Phonopticon In Its Adaptation To Enable The Blind To Read The Printed Page, F. C. Brown

Proceedings of the Iowa Academy of Science

40. The crystal phonopticon

The crystal phonopticon is an arrangement of apparatus whereby illumination characteristics (e.g. such as come from a small portion of any printed page) of variable arrangement, intensity and sequence may be transformed into sound progressions of corresponding variable intensity, arrangement, duration and sequence. It is called the Crystal Phonopticon because by the use of recently discovered crystals, of selenium light impressions are transformed into sound impressions.

Summer Term Commencement [Program], July 24, 1914, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.

Courses Of Study And Program Of Recitations, 1914-1915, Iowa State Teachers College

UNI Schedule of Classes

A listing and schedule of the courses being taught as well as policies and procedures concerning attending classes at the Iowa State Teachers College.

Spring Term Commencement [Program], June 9, 1914, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.

College Catalog And Circular 1914, Iowa State Teachers College

UNI Programs and Courses Catalogs

Table of Contents:

Calendar for 1914-1915 ... 6
Officers of Administration ... 8
Officers of Instruction ... 8
Faculty Committees 1914-1915 ... 16
Plan of Organization ... 18
Divisions of the Faculty ... 19
General Regulations ... 20
Faculty Regulations ... 23
Order and Deportment ... 23
Credits and Scheduling ... 24
Extension Service ... 24
Exchange of Students ... 25
Expenses and Fees ... 26
College Organizations ... 28
Training in Actual Teaching ... 30
Public Lectures and Entertainments ... 33
Boarding and Lodging ... 35
Requirements for Admission ... 37
Department Courses ... 43
The Diploma Courses ... …

Summer Term, Eighteenth Annual Session, 1914, Iowa State Teachers College

UNI Schedule of Classes

A listing and schedule of the courses being taught as well as policies and procedures concerning attending classes at the Iowa State Teachers College.

Equilibrium In The System: Mercuric Iodine And Anilin, E. J. Fry, J. N. Pearce

Proceedings of the Iowa Academy of Science

Those who have worked with anilin have no doubt observed its extraordinary high solvent power upon many of the inorganic salts. Like ammonia it also has the power of combining with salts to form stable crystalline compounds containing from one to as high as six molecules of anilin of crystallization.

Illuminating Power Of Kerosenes Used In Iowa, William Kunerth

Proceedings of the Iowa Academy of Science

The kerosene oil industry in the United States dates back to about the year 1850, although evidences are found in the oil producing regions of Pennsylvania which indicate that the existence of the oil was known long before that date.

Proceedings Of The Twenty-Eighth Annual Session Of The Iowa Academy Of Science: Staff & Committee Reports; Program

Proceedings of the Iowa Academy of Science

No abstract provided.

1914 Old Gold, Iowa State Teachers College

UNI Yearbooks

The student yearbook of the Iowa State Teachers College, later known as the University of Northern Iowa.

The Adaption Of Selenium To Measurements Of Energy Too Small To Be Measured By Other Devices, L. P. Sieg, F. C. Brown

Proceedings of the Iowa Academy of Science

As a brief introduction to the subject matter of this paper, a review of the various devices used in energy measurements will not be amiss. The devices are not numerous, and they are familiar to everyone at all conversant with the methods of physics. They are the thermometer, the differential thermometer, the thermopile, the bolometer, the radiomicrometer, and the radiometer. Several other devices have at different times been suggested and used, but the above represent the most important ones.

Some Evidence Of Recent Progress In Geology, George F. Kay

Proceedings of the Iowa Academy of Science

In a recent publication by President Van Hise it was stated that the data of geology have become so numerous that they are almost unmanageable. With this view all geologists will agree. Not many decades ago it was possible for a geologist to have a reasonably full and satisfactory knowledge of his own science, and, also, to be fairly familiar with the related sciences. Now it is impossible for any geologist to learn all the important facts about all the branches of his own science. Not only is this true, but no geologist can know all the discovered facts of …

Sunflecks, W. H. Davis

Proceedings of the Iowa Academy of Science

On Sunday, June 28, 1908, between 9:27 a. m., and 12:41 p. m., there occurred a seven-eighths eclipse of the sun. Thinking that I might procure some eclipse pictures, I loaded my plate-holder with 5 inch by 7 inch Standard Orthonon plates.

Notes On The Construction Of Selenium Bridges, E. O. Dieterich

Proceedings of the Iowa Academy of Science

The value or effectiveness of a selenium bridge depends upon several factors; namely: 1. The resistance of the bridge. 2. Its permanence, or stability. 3. Its sensitiveness, i.e., the ratio of the resistance of the bridge in the dark to that in the light. 4. The shape of the wave-length-sensibility curve. This paper summarizes the results of an investigation of the conditions governing the production of selenium bridges of certain types.

The Electrical Conductivity Of Solutions Of Certain Electrolytes In Organic Solvents, J. N. Pearce

Proceedings of the Iowa Academy of Science

The study of the electric conductivity of solutions in organic solvents has brought to light many interesting relations. In many such solvents the same general relation obtains as is found in the case of aqueous solutions, viz., the molecular conductivity increases regularly with increasing dilution. In the great majority of these no limiting value of the molecular conductivity is obtainable, however great the dilution employed.

The Variation Of Sound Intensity With Distance From The Source; An Interesting Case Of Deviation From The Inverse Square Law, Harold Stiles, G. W. Stewart

Proceedings of the Iowa Academy of Science

The phenomena of sound present many interesting features and diffraction is not the least. The writers have been able, by an extension of Rayleigh's theory, to determine the effect in the neighborhood of a rigid sphere produced by a source of sound located on that sphere. One of the results of this theoretical investigation is the establishment of the variation of the intensity of sound with the distance from the center of the sphere. The computations necessary for approximate numerical results are tediously long, and those given herewith are merely those that were readily available in other investigations of the …

The Formation Of Eskers, Arthur C. Trowbridge

Proceedings of the Iowa Academy of Science

Ever since work has been in progress in glaciated regions, long, narrow, winding, steep-sided, conspicuous ridges of gravel and sand have been recognized by geologists. They are best developed and were first recognized as distinct phases of drift in Sweden, where they are called Osar. The term Osar has the priority over other terms, but in this country, probably for phonic reasons, the Irish term Esker has come into use. With apologies to Sweden, Esker will be used in the present paper. Other terms which have been applied to these ridges in various parts of the world are serpent-kames, serpentine …

Fall Term Commencement [Program], November 25, 1913, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.

College Catalog And Circular 1913, Iowa State Teachers College

UNI Programs and Courses Catalogs

Table of Contents:

Calendar for 1913-1914 ... 6
Officers of Administration ... 8
Officers of Instruction ... 8
Faculty Committees 1913-1914 ... 19
Plan of Organization ... 21
Organization of the Faculty ... 23
General Regulations ... 23
Faculty Regulations ... 27
Expenses and Fees ... 28
Literary Societies ... 31
Special Certificates ... 32
Training Department in Actual Teaching ... 33
Public Lectures and Entertainments ... 38
Boarding and Lodging ... 41
Requirements for Admission ... 43
Outline of the College Course ... 45
Distribution of Credits ... 46
Professional Course of Study for College Graduates ... 55
Special …

Courses Of Study And Program Of Recitations, 1913-1914, Iowa State Teachers College

UNI Schedule of Classes

A listing and schedule of the courses being taught as well as policies and procedures concerning attending classes at the Iowa State Teachers College.

Spring Term Commencement [Program], June 10, 1913, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.

Summer Term, Seventeenth Annual Session, 1913, Iowa State Teachers College

UNI Schedule of Classes

A listing and schedule of the courses being taught as well as policies and procedures concerning attending classes at the Iowa State Teachers College.

1913 Old Gold, Iowa State Teachers College

UNI Yearbooks

The student yearbook of the Iowa State Teachers College, later known as the University of Northern Iowa.

An Experimental Investigation Of The Relation Between The Aperture Of A Telescope And The Quality Of The Image Obtained By It, Fred Vorhies

Proceedings of the Iowa Academy of Science

The subject of telescopic vision was presented to the scientific world a few years ago in a series of articles written by Dr. G. J. Stoney. At that time Dr. Stoney discussed the proposition as applied to the vision of distant planets and drew the conclusion that astronomers were not able to detect certain details upon the planet Mars. Since the appearance of this series of articles a considerable discussion has taken place but no definite conclusions have been drawn.

A Case Of Urticaria Factitia Observed In The Coe College Psychological Laboratory, W. S. Newell

Proceedings of the Iowa Academy of Science

Record of an unusual affection which appeared in experimental work in tactual space. In submitting the following record upon a case of Urticaria, the writer has intentionally observed two restrictions, (1) to leave the technical discussion of the disease in question to medical treatises, (2) to avoid unwarrantable generalization from a single case under observation. While conforming with these limitations, it has seemed that a record of the case, giving such concrete details of the appearance, the progress and the peculiarities of the disease as it was studied in our laboratory, might leave deductions and generalizations to await the discovery …

The Use Of The Rayleigh Disk In The Determination Of Relative Sound Intensities, Harold Stiles

Proceedings of the Iowa Academy of Science

In the second volume of his Theory of Sound, Lord Rayleigh presents a method for determining mathematically the intensity of sound at very great distances from a rigid sphere, the source of sound being confined to a small area on its surface. Prof. G.W. Stewart has extended the work of Rayleigh and has calculated the relative sound intensities for sets of points lying on circles concentric with the sphere, the planes of these circles also passing through the source of sound. The points on any one circle were 15 degrees apart and the diameters of the four circles used were …

On The Existence Of A Minimum Volume In Solution, Leroy D. Weld

Proceedings of the Iowa Academy of Science

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.

Spring Term Commencement [Program], June 11, 1912, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.