Indiana State University - Sycamore Yearbook (Terre Haute, IN)

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12 . THE NORMAL ADVANCE as x- was known Ivery early. In 1269 it is believed to have been khoWn in Europe, although some doubts are expressed c'oneeining this. At any rate Columbus is said to have noticed the. Var- ring of the tidipll about 1480. Some accounts state that it was known to the Chinese as eafly as the eleventh century. The first real work to get at the causes, or to show the nature of this strange phenomena was done by Gilbert in the sixteenth century. His primary thesis was that-the globe consists of a certain solid homogenous substance, firmly coj herent and endowed with primordial proper- ties. The Various substances which appear at the surface of the globe through contact with the atmospheric waters, and influence of the heavenly bodies, have become deprived of the prime qualities, properties and true nature of terrene matter. But lodestone and all magnetic substances contain the potency of the earth,s core and its imnost viscera, in virtue of which the earth itself remainsfin'p'osi'tion and is di- ' rected in its movements. Thus, reasons Gilbert, the earth is a huge magnet, or the lodestone is a fragment of the magnetic earth which possesSes the primal form of terrestrial bodies. In other words Gilbert thinks that the magnetic qual- ities of the earth are due to the core, which is made up of lodestone and other magnetic sub- stances. The investigations made by Gilbert in sup- port of his theory are very interesting and logical. They consist first, in determining what a magnet is. Second, the cause and char- acter of magnetic attractions, and third, the nature of its polarity. Having found certain phenomena of the lodestone true of the earth, and conversely certain terrestrial phenomena true in a miniature earth made of lodestone, he concludes the earth itself to be a magnet. The research begins with a comparison of the poles of the heavens, the poles of the earth and the poles of lodestone; the proposition is at once laid down that the poles of magnet on the earth look towards the poles of the earth, move towards them and are subject to them. This was the first statement of the truth that xxg the compass needle is governedenot by the poles of the heavens, or by the 'pole star, but by the magnetic quality of the globe itself. . In order to prove the like natu're of the earth and lodestone, Gilbert carved a piece of the stone into Spherical form. Thisminiature earth he called an ttearthkinll 0r ttterrellay and upon this he made his experiments mainly by placing near to it pivoted iron needles or plates, and noting the directive 0r attractive force ex- erted by this globe. Another theory similar somewhat to Gilbertls is that the crust contains an abundance of iron and other less strongly magnetizable metals. Iron pervades all ttprimaryll and ttsecondaryll rocks and forms an essential part of innumer- able minerals. But the source of this magnet- ism is not clear. The least unsatisfactory ex- planation seems to be something like this: ttThe earth turning towards the east, offers the more westerly parts of its surface to solar radiation. The thermal eifect is the same as though a fiood of heat travelled around the earth from east to west. We have seen many in- stances which show that heat and electricity travel together, that in a closed circuit, if we can get heat to circulate, the current travels with it. There may, therefore, be prevailing earth currents moving with the sun from east to west around the earth. The earth being mag- netizable, these currents would convert it into an electro-magnet. The light of the aurora, which seems to have its greatest activity at the poles, is not unlike the light seen on making a strong electro-magnet in a dark room. With all that has been discoVered regarding the nature of the earthls magnetism, there re- mains a great deal to be discovered before its nature will be clearly understood. The practical application of the earthls mag- netic field and the ttsettingl, property of a sus- pended needle is made use of in navigation. The magnetic needle which is used by sailors is much more elaborate than the ordinary pivoted needle. The mariner,s compass now used was designed by Lord Kelvin. Instead of having a needle swinging over a circle on which

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THE NORMAL ADVANCEI 11 largely internal, we feel that we are dealing with matters in which good and bad result di- rectly from our own choice. Whether my thoughts go up or down, whether I am sincere or a hypocrite in my own heart, I can not easily escape the conviction that it is because I choose to be so. For I may guard the sanctuary of my soul to a very large degree, if I will, and what goes on within is my own. But not so upon the stage of the life outside, where I am only one among countless others, and where this and that may so easily interfere, which I can not help, and which will seem to excuse any failure 01' shortcoming on my part. An evil deed is readily accounted for by the iniiuence of our environment, and if we agree to surrender our- selves to our environment and give it the place which it claims, the individual can no longer be blamed for what he does. Hence comes our leniency toward all crime, our readiness to as- sume that a man means well even. when he does ill, and above all, that deep-seated casuistry of so many of the doers of our deeds, by which anything may seem allowable if looked at from some point of view. There is one remedyeto restore the inner life, the conscience, to its proper place as the arbiter of our deeds. But this means that we must give thought to this inner life, and not allow things external to encroach upon it or rob it of its vitality. To perform its full duty of regulating our outer life, it must have grown to full stature by the rule of right which nature gave it. It is out of the abundance ofthe heart that the mouth speaketh, not out of the abund- ance of things seen or heard. But you will ob- serve that this presupposes an abundant heart to begin with. DEPARTMENT OF SCIENCE it Terrestrial Magnetism ,, RAY JARED, '10 If we could conceive a huge magnet thrust through the axis of rotation of the earth, hav- ing its north seeking pole at the south geo- grapical pole and the south seeking pole at the north geographical pole, we would get the first crude notion of the earthls magnetism. By the action of such a magnet a magnetic needle at the equator would stand in a hori- zontal position and would remain horizontal at all points on the equator. Advancing poleward we should, in the northern hemisphere, find that the needle loses its horizontal position and dips more and more so that if produced it would cut the earth. At the north pole the needle would stand vertically with its north seeking pole downwards. Subj ect to certain alterations this is just what happens when we travel with a magnetic needle about the earth; and accordingly the earth is regarded as a huge spherical magnet having its north seeking pole at the crown of the southern hemisphere and its south seeking pole at the crown of the northern hemisphere. Thus we see that the earth is in some ways a huge magnet and has in consequence a magnetic field. The distribution of the field upon the surface of the earth is similar to that of a field sur- rounding a bar magnet placed at the center of the earth, the only difference being that the field of a bar magnet would be quite regular and equal while the magnetic field of the earth is more or less irregular. At any one place, however, the field may be regarded as being uniform. Now a freely suspended needle would set itself along the lines of force at any place and if such a needle were carried round the eaI'th,s surface from the north pole to the south pole it would be found to take up different positions and set at diEerent angles with the horizon at the different places on the earth. Such actions of the needle is called ttdipping. This fact, the dipping of a magnetic needle,

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:THEvNORMAL ADVANCE , a 13 the points of a compassare marked, a circular piece of card is pivoted so that it can turn in a horizontal plane. On the'under side of the card a number of small magnets are fixed With their marked poles pointing in one direction. This arrangement obviates any error of their magnetic axes not being parallel to their edges. The magnets are attached to the card so as to be parallel to a line joining north and south. As the card is only free to turn in a horizontal plane, the box must be suspended so that it al- ways remains horizontal however much the ship may roll. , In order to take a shipls bearings at any place, the angle of declination, or ttdipi, at that place must be known or else the captain would not know which way to head his boat in order to arrive at a certain place, For this purpose magnetic charts are drawn up upon which lines of equal declir ion are marked. A line is drawn througi ll places at which the declina- tions are equa. This is termed an ttisogonici, line. Thus the declination at the various parts of the world are mapped out by isogonic lines. A line joining the places at which the declina- tion is 00, that is where. the magnetic meridian coincides with the geographical meridian is called an agonic line. The reading of the angle of declination of the place at which, the boat is located, is compared to the chart and the line that coincides with reading of the ship, shows just where the ship is with reference to the land or place that the boat may be going. Preservation of Wood MILTON, B. NUGENT, '10 One of the great problems of the day is how to make theisupply of wood equal the demand. At present the forests are decreasing rapidly, and the demand for wood and wood products is increasing at even a greater rate, so it is only a question of time until the supply of woodwill be exhausted, if steps are not taken to stop the wasteful use of it, or to keep up the forests by tree culture. Increasing the forests is a mat- ter of time as it takes seventy-five to one hun- dred twenty years for a timber tree to mature. The first problem, that of using the available wood most economically is the most pressing one. Great corporations, such as railroads, bridge companies, etc., have undertaken to lessen the demand, that is, use to the best possible advant- age the wood they have, so they have hit upon the plan of preserving the timber, in use, by chemical treatment. The railroad companies, which use enormous quantities of wood for ties,ihave, for a long time, felt the need of lengthening the life of ties. , At first, such woods as white oak and other hard woods were plentiful, so they were used. But now the scarcity of hard woods com- . pels them to use pine, cottonwood, maple, etc. This entails a great deal of expense as the life of a soft wood tie is very short. As a result, they have begun experimenting with processes for preserving the wood. The results have been very satisfactory. Perhaps the best system for the preservation of wood is that of creosoting. The only ob- jection to this plan is the high price of creosote oil, and the consequent expense of the treated ties. There are two kinds of creosote used: tll dead oil of coal tar, ml wood'creosote oil. The latter is the cheaper but not as good as the coal tar. One company that has tried the wood creosote has abandoned it. They found that its life as an antiseptic is short, it being easily soluble in water. The process of creosoting consists of placing the ties in a large iron cylinder. The air is then exhausted, the ties heated by steam to soften the cell walls, and dissolve the contents of the cells, and then hot creosote is forced in