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Smoke Makes City Warmer

Science Bulletin

Mr. Fred L. Disterdick, of the U. S. Weather Bureau at Des Moines, has observed surprisingly great differences in temperature between the smoke covered city and the nearby country.

Editor And Advisory Board

Science Bulletin

A Service Bulletin for Teachers of High School Science.

Universe May Not Be Running Down

Science Bulletin

The Sun by radiation is losing energy at a tremendous rate. The Earth receives about one two thousand millionth part of this, and other planets, satellites and asteroids their tiny share. The rest travels out into the depths of space, presumably to be lost forever so far as the solar system is concerned.

Plant Disease Control, C. W. Lantz

Science Bulletin

In the November issue of the Bulletin some idea of the crop losses due to plant diseases was given. Obviously the farmer should be concerned in preventing these losses if he is to profit most from his labor. The control of plant disease lies in prevention rather than cure. In most cases, the individual plant is not of sufficient value to warrant an attempt to cure it. The exceptions would be in those cases where a valuable individual plant such as a shade tree becomes diseased and it would be desirable to save it.

Science Bulletin, Vol.3 No.5, January 1931 [Complete Issue]

Science Bulletin

A Service Bulletin for Teachers of High School Science.

Title Page

Science Bulletin

A Service Bulletin for Teachers of High School Science.

Question Box, W. H. Kadesch, O. R. Clark, Winfield Scott

Science Bulletin

Question: Wood is opaque to light but is easily penetrated by X rays. The latter, however, are stopped by some kinds of clear glass. Does this not show that light and X rays are of different nature?

Is it desirable to study the theory of evolution in connection with a high school course in Botany? If so, to what extent?

What is the purpose of crop rotation?

On Meeting With A Fox, Roy L. Abbott

Science Bulletin

It is rarely that one sees a wild animal at its best. As a hunter, I have shot many beautiful birds and small mammals, but on retrieving them, in spite of my elation at their capture, I have always had the haunting feeling that the dead thing in my hand was not the creature at which I had aimed. As an anatomist, I have dissected scores of animals, but always do I realize that the stiff, cold thing under my scalpel is not quite the thing it was when alive.

Radio And The Outer Atmosphere

Science Bulletin

In investigating the possibilities of short-wave radio the surprising fact was discovered that although short waves may often be clearly received at distances of thousands of miles from stations with very little power, it is difficult or impossible to detect them at nearby points, 30 to 300 miles away. This can be understood if the upper atmosphere acts like a reflector.

About Atmospheric Electricity, L. Begeman

Science Bulletin

Our atmosphere is electrified at all times. During the summer the average increase of potential from the earth's surface up is about 100 volts for one meter of ascent. This potential gradient, however, diminishes with increasing altitude until at the height of one mile it is only 25 volts per meter. During the winter the atmosphere is much more in tensely electrified. The average increase of electrical potential near the earth 's surface during this season is as much as 250 volts per meter of ascent.

Test 185: Rumely Model 6a, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 191: Massey-Harris "General Purpose", Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 195: Cletrac Model 40-30, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 186: Bates Steel Mule Model 35, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 196: Cletrac Model 15, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 197: Minneapolis- Moline Universal Model Mt, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 194: Mccormick Deering Industrial Model 20, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 189: Allis-Chalmers "All Crop", Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 190: John Deere Gp, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT: John Deere GP

TEST A: The manufacturer's representative operates the tractor for a minimum of 12 hours using light to heavy drawbar loads in each gear.

This serves as a period for limber up, general observation and adjustments. Adjustments that are permissible include valve tappet clearance, breaker ,point gap, spark plug gaps, clutch and others of a similar nature. No new parts or accessories can be installed without having mention made of it in the report. No data' are recorded during this preliminary run except the time that the engine is operated.

BELT HORSEPOWER TESTS

TEST …

Test 187: Bates Steel Mule Model 45, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 192: Bradley "General Purpose", Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 193: Allis Chalmers Model Ek, Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 198: Mccormick-Deering Farmall "F-30", Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Test 199: Mccormick-Deering "Tractractor", Nebraska Tractor Test Lab

Nebraska Tractor Tests

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Science Bulletin, Vol.3 No.4, December 1930 [Complete Issue]

Science Bulletin

A Service Bulletin for Teachers of High School Science.

The Nature Of Adaptations, O. R. Clark

Science Bulletin

In the October number of this bulletin, in a discussion of the influence of environment upon the growth and development of plants, the statement was made that, on the whole, plants are quite well adapted to the conditions under which they grow. As to the manner by which this ''fitness” has arisen there are some differences of opinion and, in the opinion of the writer, a great many misunderstandings. This is a question to which no ''cut-and-dried'' answer can be given but to which a fundamental principle of biology may be applied.

Nobel Prizes For 1930

Science Bulletin

The Nobel prizes in science, each amounting to nearly $50,000, have recently been awarded, as follows.

Editor And Advisory Board

Science Bulletin

A Service Bulletin for Teachers of High School Science.

Fossils Of Three Toed Horse In Wyoming

Science Bulletin

An expedition of the Harvard University Museum of Comparative Zoology, under the leadership of Erich M. Schlaikjer, has recently discovered near Torrington, Wyoming, an enormous fossil deposit in which were found thousands of little three toed horses that lived about 35,000,000 years ago.

Farming In India, Winfield Scott

Science Bulletin

The following extract from an article written by Saint Mhal Singh of India (See Wallace's Farmer, April 30, 1909) is given as a description of farmers in that populous country. The Hindoos are the Eastern Branch of our own Aryan race.