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Vacuum Tube Circuits As A Source Of Power For Conductivity Measurements, H. A. Geaque, F. Paul Ralston Jan 1920

Vacuum Tube Circuits As A Source Of Power For Conductivity Measurements, H. A. Geaque, F. Paul Ralston

Proceedings of the Iowa Academy of Science

At the present the possible sources of current for conductivity measurements are limited to the induction coil, the high frequency generator and the Vreeland oscillator. In the first two the oscillating current is produced mechanically and the noise from the mechanism is apt to interfere with the accurate balancing of the bridge when measuring the resistance of the conductivity cell. This may not be the greatest objection in the case of the induction coil as it has been shown that the current has an undirectional value. The Vreeland oscillator is the only apparatus in use which produces a tunable oscillating …


A Field Of Eskers In Central Iowa, John E. Smith Jan 1920

A Field Of Eskers In Central Iowa, John E. Smith

Proceedings of the Iowa Academy of Science

This area is located chiefly in Polk County, one to three miles west of Camp Dodge in a swampy section of the south side of Beaver Creek valley. It is just north of the recessional moraine that extends in an east-west direction across parts of Polk and Dallas counties. Within an area about a mile wide and two or three miles long lying mostly in sections 19 and 20 of Jefferson township, there are a dozen or more eskers which the writer first studied during observations made in this locality in 1910.


Swimming Pool Sanitation, Jack J. Hinman Jr. Jan 1920

Swimming Pool Sanitation, Jack J. Hinman Jr.

Proceedings of the Iowa Academy of Science

The swimming pool, being really a sort of common bath, rapidly departs from a sanitary condition, unless prompt and adequate measures are taken to maintain a reasonable degree of purity in the water. Moreover, since various types of intestinal infections, infections of the respiratory system, eye and ear infections, gonorrheal infections and skin infections have been traced to the waters of swimming pools, the protection of the bathers by means of proper treatment of the water and rigid inspection of all entrants into the pool is essential to safety.


The Alumni News Letter, V3n2 [V4n1], January 1, 1920, Iowa State Teachers College Jan 1920

The Alumni News Letter, V3n2 [V4n1], January 1, 1920, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.


The Major Vegetation Of Lake Okoboji, Robert B. Wylie Jan 1920

The Major Vegetation Of Lake Okoboji, Robert B. Wylie

Proceedings of the Iowa Academy of Science

The major vegetation of Lake Okoboji consists chiefly of submersed seed plants. The algae are always in evidence and play an important part in the life of the lake since they are used as food by many lower animals, but with the exception of Chara they are seldom conspicuous and never large.


Comparison Of Absorption Occuring In Corn Stalk Tissue And In Prepared Biocolloids, L. E. Yocum, A. L. Bakke Jan 1920

Comparison Of Absorption Occuring In Corn Stalk Tissue And In Prepared Biocolloids, L. E. Yocum, A. L. Bakke

Proceedings of the Iowa Academy of Science

Growth, an important function of the plant, is characterized by being possible under a wide range of temperature, moisture, available plant food, and other limiting factors. It is a hydration of the colloidal material (protoplasm) of the plant to which, later in the life of the plant, matter is added. This added matter, of course, increases the dry weight. Protoplasm has been found to adhere so closely in its actions to the laws of artificially constructed biocolloids that many attempts are being made to construct a biocolloid whose behavior agrees with the observed behavior of protoplasm and in that way …


The Relation Of The Smaller Forest Areas In Non-Forested Regions To Evaporation And Movement Of Soil Water, Irwin T. Bode Jan 1920

The Relation Of The Smaller Forest Areas In Non-Forested Regions To Evaporation And Movement Of Soil Water, Irwin T. Bode

Proceedings of the Iowa Academy of Science

The importance of the climatic and edaphic relations of forests has been the basis for wide discussion and study. The scope of this field is shown in a condensed way in a report of the Sub-Committee on Forest Investigations to the Fifth National Conservation Congress, which discusses studies undertaken up to the time of the report (1913) and presents in general results obtained. Recently, Zon, in a paper, "Forests and Water in the Light of Scientific Investigation," has presented a much more comprehensive view of the subject and the literature. He has attempted to bring together "all the well-established scientific …


A Study Of Sociality In The Madreporaria, Gertrude Van Wagenen, H. J. Wehman Jan 1920

A Study Of Sociality In The Madreporaria, Gertrude Van Wagenen, H. J. Wehman

Proceedings of the Iowa Academy of Science

The type of sociality found in the Madreporaria is necessarily primitive. While we were making this study two criteria of sociality have been adopted and applied: first, the proximity of one corallite to another; second, organic communication between associated polyps and corallites. As the two criteria indicate, sociality is examined from the standpoint of morphology of hard parts. This is necessary because of the extent of the field covered, the absence of live specimens, and the inclusion of fossils.


1920 Old Gold, Iowa State Teachers College Jan 1920

1920 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.


Notes On Some Plants Of The Arapahoe National Forest And Rocky Mountain National Park, L. H. Pammel, R. I. Cratty Jan 1920

Notes On Some Plants Of The Arapahoe National Forest And Rocky Mountain National Park, L. H. Pammel, R. I. Cratty

Proceedings of the Iowa Academy of Science

One of us accepted an invitation to spend ten days in August, 1919, with the forestry students and Professor G. B. MacDonald, Professor G. C. Morbeck and Mr. D. C. Poshusta in the Arapahoe national forest. The camp was located at the junction of Spruce creek and the fork of St. Louis creek, near the ranger station, at an altitude of about 9,000 feet.


A Note On A Sink Hole, E. J. Cable Jan 1920

A Note On A Sink Hole, E. J. Cable

Proceedings of the Iowa Academy of Science

Most sink holes occur in regions where the underlying rock is dominantly calcareous. They are variously shaped depressions in the surface into which the run-off is carried away as subterranean drainage.


A Note Of Progress On The Study Of The Iowan-Wisconsin Borders, E. J. Cable Jan 1920

A Note Of Progress On The Study Of The Iowan-Wisconsin Borders, E. J. Cable

Proceedings of the Iowa Academy of Science

During the past year the writer has found some time to continue his investigations of the Iowan and Wisconsin borders. As stated in a former article, there is a strong field of evidence that the Iowan margin in Hardin and Grundy counties will need to be revised, especially in the vicinity of Eldora, Hardin County. Owing to the thinness of the Iowan drift, the high state of its weathering, and its complex relations to the loess, much more detailed work will be necessary before a definite boundary can be determined upon.


The Personal Equation In Motor Ability, Martin L. Reymert Jan 1920

The Personal Equation In Motor Ability, Martin L. Reymert

Proceedings of the Iowa Academy of Science

In order to try out experimentally the common notion, that an individual will show a constant behaviour as to speed and accuracy in all kinds of motor performance - within his group - a series of reaction and motor tests were given to sophomores. The tests were: (1) Tapping in group (with pencil). (2) Individual tapping (on telegraph key). (3) Counting numbers orally. (4) Writing numbers. (5) Counting and writing as one combined activity. Simple bodily reactions of (6) the lips, (7) the jaws, (8) the index finger, (9) the head, (10) the elbow, (11) the thumb, (12) the foot. …


The Iowa Pitch Range Audiometer, C. C. Bunch Jan 1920

The Iowa Pitch Range Audiometer, C. C. Bunch

Proceedings of the Iowa Academy of Science

The ideal apparatus for measuring the acuity of the ear should enable one to determine the faintest audible sound at each and every pitch within the tonal range. It should be easily and quickly operated and should be permanently standardized. The Pitch Range Audiometer is an approach to this ideal.


Officers, Past Presidents, And Members, Iowa Academy Of Science Jan 1920

Officers, Past Presidents, And Members, Iowa Academy Of Science

Proceedings of the Iowa Academy of Science

No abstract provided.


Title Page - Front Matter Jan 1920

Title Page - Front Matter

Proceedings of the Iowa Academy of Science

No abstract provided.


Proceedings Of The Thirty-Fourth Annual Session (Of The Iowa Academy Of Science), Held At Iowa City, April 23 And 24, 1920: Minutes Of The Meeting; Staff & Committee Reports Jan 1920

Proceedings Of The Thirty-Fourth Annual Session (Of The Iowa Academy Of Science), Held At Iowa City, April 23 And 24, 1920: Minutes Of The Meeting; Staff & Committee Reports

Proceedings of the Iowa Academy of Science

No abstract provided.


Presentation Of The Calvin Memorial Portrait; Addresses Pertaining To The Presentation Of The Calvin Memorial Portrait, Thomas H. Macbride, L. H. Pammel, M. F. Arey, B. Shimek, A. O. Thomas, Edgar R. Harlan Jan 1920

Presentation Of The Calvin Memorial Portrait; Addresses Pertaining To The Presentation Of The Calvin Memorial Portrait, Thomas H. Macbride, L. H. Pammel, M. F. Arey, B. Shimek, A. O. Thomas, Edgar R. Harlan

Proceedings of the Iowa Academy of Science

No abstract provided.


The Hall Effect And The Specific Resistance Of Thin Silver Films, G. R. Wait Jan 1920

The Hall Effect And The Specific Resistance Of Thin Silver Films, G. R. Wait

Proceedings of the Iowa Academy of Science

The Hall Effect of ordinary metals may be expressed by the equation E=HIa/e where E = the Hall Effect, I= the primary current, e= the thickness of the conductor and a= a constant whose value in silver lies between.00083 to.00090. In the present investigation the above equation was found to hold in thin silver films, and that has a value of.00084.


Table Of Contents Jan 1920

Table Of Contents

Proceedings of the Iowa Academy of Science

No abstract provided.


The Vegetation Of Cape Blanco, Morton E. Peck Jan 1920

The Vegetation Of Cape Blanco, Morton E. Peck

Proceedings of the Iowa Academy of Science

To most of us the name of Cape Blanco has a familiar sound, bringing back as it does recollections of the geography lessons of our early school days, when we learned that it was the most westerly point of the United States south of Alaska. We may possibly have learned also that it is one of the most dangerous points for vessels on our western coast. Beyond these two brief facts the knowledge of very few of us extends.


The Selection Of Talent For Stenography And Typing, Benjamin W. Robinson Jan 1920

The Selection Of Talent For Stenography And Typing, Benjamin W. Robinson

Proceedings of the Iowa Academy of Science

H. C. Link states that "The application of psychological tests in those fields where their value has been verified, is the only method short of the laborious and costly method of trial and error, which makes it possible to discover the exact ability, both innate and acquired, of an individual. Unless these facts are known, it becomes impossible to assign the individual to the work for which he is best fitted or to give him the training which he deserves. Once the potential and actual ability of an individual has been discovered the vocational selection or training of that individual …


The Address Of The President - The Taxonomic Unit, T. C. Stephens Jan 1920

The Address Of The President - The Taxonomic Unit, T. C. Stephens

Proceedings of the Iowa Academy of Science

The retiring president is expected to follow the custom of addressing the Academy upon some subject of general interest. Fortunately, custom does not require that such an address shall embody one's own research or investigation; but it may consist of a survey, or of reflections of a general nature. It so happens that certain fields in which I have been somewhat interested have brought me to a study of the problem of the taxonomic unit in biology.


The Germination Of Some Trees And Shrubs And Their Juvenile Forms, L. H. Pammel, C. M. King Jan 1920

The Germination Of Some Trees And Shrubs And Their Juvenile Forms, L. H. Pammel, C. M. King

Proceedings of the Iowa Academy of Science

In our studies of seedlings during the year 1918-1919 there have been included representatives of the following families: Salicaceae, Urticaceae, Berberidaceae, Leguminosae, Rutaceae, Vitaceae, Cornaceae, Sapotaceae and Oleaceae.


Notes On The Distribution Of Midsummer Bee Plants In The Mississippi Zone Of Clayton County, Ada Hayden Jan 1920

Notes On The Distribution Of Midsummer Bee Plants In The Mississippi Zone Of Clayton County, Ada Hayden

Proceedings of the Iowa Academy of Science

With intent to determine (1) what plants were available to bees in late summer, (2) how these plants were located with reference to water reservoirs and (3) which of these plants were most valuable to the bee, some observations were made in Clayton County, Iowa, August 20 to September 9, 1919. The vicinity of McGregor, Beulah, Garnavillo, Guttenberg, Clayton. Prairie-du-Chien, and some of the adjacent islands of the Mississippi about McGregor were visited. Since the water supply is related to the topography and the distribution of plants is relative to both these factors, the geology and topography should be kept …


Agricultural Geology, John E. Smith Jan 1920

Agricultural Geology, John E. Smith

Proceedings of the Iowa Academy of Science

During reconstruction, as the present period is frequently termed, many new applications of the principles of pure science to special fields of endeavor are being made. The principles of geology thus applied during recent years have given rise to economic geology, mining geology, engineering geology, oil geology and perhaps to that branch of the subject indicated by the above title, for it is not entirely new. The application of the principles of the science to the solution of the geological problems that are met in agricultural enterprises and pursuits, in brief, the relation of geology to rural welfare may appropriately …


The Dependence Of The Resistance Of Silver Films Upon The Method Of Deposition, G. R. Wait Jan 1920

The Dependence Of The Resistance Of Silver Films Upon The Method Of Deposition, G. R. Wait

Proceedings of the Iowa Academy of Science

Most observers investigating the specific resistance in thin metallic films have found that it decreases rapidly with time. In the present investigation Brashear's process of obtaining silver films was followed.


A New High Frequency Tone Generator, C. W. Hewlett Jan 1920

A New High Frequency Tone Generator, C. W. Hewlett

Proceedings of the Iowa Academy of Science

Ordinary telephone receivers will respond satisfactorily to alternating currents at frequencies as high as ten thousand vibrations per second, but above this frequency so much of the electrical energy is absorbed in hysteresis and eddy current loss that it becomes impracticable to supply enough energy to the receiver to enable it to serve as a satisfactory source of sound waves.


The Comparative Stability Of Colors In Wallpaper, J. M. Lindly Jan 1920

The Comparative Stability Of Colors In Wallpaper, J. M. Lindly

Proceedings of the Iowa Academy of Science

The salesman of wallpaper is frequently asked if such a sample will fade, or is confronted with the bold assertion that such a specimen will do so. Usually, he is unable to answer the question definitely, or to deny the charge. Not having noticed any observation on the subject of the stability of colors in wallpaper, the writer was prompted to make a few tests or experiments.


The Measurement Of Motility In Children, Lillian Tow Jan 1920

The Measurement Of Motility In Children, Lillian Tow

Proceedings of the Iowa Academy of Science

What we expect and demand in discipline and performance at each age should depend upon a child's development, mental, physical, and functional. In this laboratory the evaluation for scientific and diagnostic purposes of motor rather than mental capacities is being stressed. The object of this investigation is to find what the motor equipment of children is on entering school. The discovery of the basic motor tests which applied at five and six years of age will give results which are reliable and significant in that they throw light on motor ability. Previous investigations on young children have had for their …