western part of the United States, the remains of the earliest having gone partly into the succeeding generations. It is clear that it would be difficult to find from this tangled mass of evidence the length of time required for all the changes to take place; but in the polar regions, the conditions have probably been on the whole very much simpler. Doubtless for a considerable fraction of the whole time these areas have been so covered with snow and ice that the disintegrating effects of air and water have been at a minimum. It is probable that because of this simplicity, it will be possible to throw some light on such great geological problems as that of the age of the earth.

The earth is in a general way a great magnet, whose magnetic poles are a few hundred miles from the terrestrial poles. It is fortunate for navigation that the earth is a magnet, for otherwise sailors who are out of sight of land could not determine their directions except when the heavenly bodies are visible. The reason why the earth is a magnet and the precise character of its magnetism are yet unknown. The magnetic needle does not in general point exactly north or south, but has many local variations doubtless due to the internal constitution of the earth. When the magnetic condition of the earth is fully determined, the results may be of the highest importance, for example, in locating great deposits of iron. If the human race shall use in the thousands of generations which are to follow as much iron as is being used at the present time, the importance of this becomes evident. The earth's magnetism is considered of so much general scientific importance at present that all the principal governments of the world are making observations of it, and The Carnegie Institution of Washington is spending nearly one hundred thousand dollars a year on investigations in this direction.

It seems not unlikely that a study of the earth's magnetism will lead to a discovery of the first magnitude respecting possibly the nature of matter and electricity. The very fact that at the present time it is quite unexplained, while it is an easily observed phenomenon, means that our knowledge in such directions is quite deficient. But when it becomes complete

it will be an important achievement. In making it complete, observations in the polar regions, especially in the neighborhood of the magnetic poles, will probably play an important part.

Another phenomenon which is probably associated with the magnetism of the earth is those mysterious, quivering lights which are known in the north as the Aurora Borealis, and in the south as the Aurora Australis. They can best be studied in high latitudes. From observations of the more definite streamers made at some distance apart, the height of the atmosphere can be determined. In fact, this is one of the best means of measuring how high its more tenuous parts extend.

The tides of the ocean are produced by the moon, and to some extent by the sun. Their magnitudes depend upon the intensity of the forces which the moon and sun exert, upon the shape of the ocean basins, and upon the rigidity of the earth. While the causes of the tides are fully understood and while they can be predicted in a general way, they present, nevertheless, many puzzling questions. In order to answer these questions it is necessary to have accurate and long-continued tidal observations made at all parts of the earth. For this reason alone it is important to have tidal observations made in the polar regions.

There is an important question connected with tidal phenomena which can be answered better from observations made in high latitudes than from those made in any other. That question pertains to the rigidity of the earth. The reason that observations made in high latitudes are particularly important in answering this question is that its solution depends mostly on the consideration of tides whose period is two weeks. These tides are due to the monthly northward and southward motion of the moon. This produces a corresponding northward and southward motion of the tidal forces and causes the so-called fortnightly tides. These tides are conspicuous in high latitudes and are observed there to the greatest advantage because there they are not so much tangled up with other tides.

Tidal observations, as well as a number of other things, now prove that the earth is solid through and through and

on the average more rigid than steel. This conclusion is, of course, quite at variance with that formerly held when it was supposed that the earth is composed of a relatively thin crust floating on a liquid interior. It does not mean, though, that the interior of the earth is not hot. As a matter of fact, its temperature is very high and far beyond the melting point of ordinary substances, but in the depths of the earth they are held in the solid state by the enormous pressure to which they are subjected.

One of the great problems of the biologist is to find out how and to what extent plants and animals change under changing environment. In some respects the polar regions are particularly good places to make discoveries in this direction. It is certain from the remains which have been found that once at least they enjoyed a temperate climate. In those days plant and animal life flourished there in abundance and was adapted to its environment. When the climatic conditions began to become colder and less congenial, these organisms found themselves subject to steadily changing conditions. Some of the forms of life entirely perished, and others were

The South Pole (marked by the Norwegian flag) photographed on the day it was discovered, December 14, 1911.

modified so as to be able to live in their altered surroundings. What actually happened can be determined from the fossil remains deposited in the rocks and the species of animals which still exist.

The record of life in the south polar regions will have to be made out almost entirely from the fossil forms because the climatic conditions on the Antarctic Continent are now so severe that all its mammals have entirely perished. No white bears climb over its great ice fields and no foxes scurry across its frozen wastes, but many kinds of whales and seals are found in the waters which wash its shores. Unfortunately most of the whales are of a useless kind. The most numerous ones, known as the "Killers", are so abundant and so ferocious that it is said hardly a seal is found which does not bear the marks of their murderous teeth. Vegetation on the Antarctic Continent is now represented only by a few low forms of mosses and lichens.

Animal life is still abundant on the coasts of Greenland and on the smaller islands of the Arctic Sea. It is this fact alone which enables the Eskimos to maintain their existence in those northern regions. Even at the extreme northern

N the factory of a manufacturing company at Providence, Rhode Island, it was decided recently to call into service the moving picture camera man to speed up labor. This was at the suggestion of a modern business expert.

As a preliminary, the first task was to make an organization chart showing the exact locations of the various departments of the factory, and of every machine on every floor. Then a "route engineer" examined minutely every product in the factory, from raw material to finished machine, and made a survey of the administrative offices.

Next, a model was built of the plant, and, with tapes of different colors, the manner in which the various parts under construction passed from department to department was shown. By following the course of a string of a certain color, one could see instantly the progress of

that material in its different forms. "Waste motions," caused through the inconvenient situation of the various departments through which a given piece of machinery must pass, were thus clearly outlined. Then began the work of shortening the strings, or, in other words, arranging the departments in the natural order of the material's progress.

Finally the moving picture machine was called into play. It made its début in the assembling of a braiding machine. The various parts of this machine came from the different departments of the factory, and the assembler was confronted with the complicated task of putting them together. The method previously in vogue was for the assembler to take the base of the machine, hunt around for the first support, put it in position, then hunt around for the second piece, put that in place, and so on until the completed machine stood ready for