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

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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

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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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14 THE NORMAL ADVANCE W W: under high pressure. In the course of the creosoting process the sap should be thoroughly extracted, and the oil forced into the wood, for the wear of the rail may cut through the sur- face and leave the thus exposed interior of the tie to decay. The following account makes the creosoting process clear. The timber is placed on cars and run into the large iron cylinder. This is then hermetically sealed, and the air pumped out. Live steam is then forced in, destroying the vacuum and giving a temperature of 125 de- grees F . This requires about fifty minutes. The vacuum pump is then started, creating another vacuum. This is done to open the pores of the wood. This requires about fifteen or twenty minutes. Live steam is again forced into the cylinder and the pressure raised to thirty pounds per square inch. This pressure is main- tained from siX to eight hours, according to the condition of the wood. Then the vacuum pump is started again, creating the third vacuum. While this is in progress the tem- perature is raised to about 225 degrees F. The third vacuum is maintained for about five hours, and then the creosote is forced in at the . temperature of 170 degrees F. The pumps are again started and the pressure raised to about ninety pounds per square inch. This pressure is kept up for from one to two hours, after Which the cylinders are opened and the charge drawn out. The Whole process consumes from eighteen to twenty hours. The average amount of creosote is one and three-fourthsgallons per cubic foot of wood. The cost is from $12 to $14 per thousand feet. The average life of the hard wood ties is doubled7 and that of the softer woods trebled and even quadrupled. Some figures show that creosoted ties . in northern F rance lasted twenty-seven years. Cottonwood and maple ties without creosote last three or four years, while creosoted ones last from ten to fourteen years. Another process which has been thoroughly tried out is that of Burnettizing. The process is similar to that of creosoting, but instead of creosote zinc-chloride is used. Here, the time required is shorter, being only from ten to twelve hours. ' The zinc solution, unlike the creosote, is not heated. It has the property of hardenng the wood but makes it brittle. Ties treated in this way are liable to split if exposed to the hot sun, and they cannot be used in damp soil as the , moisture extracts the solution. The rules of the companies using the Burnettized ties are that they should be used only in dry cool regions. To overcome the objections to Burnettized wood When used in damp soil or atmosphere, there are several auxiliary processes. The best. i known of these is the Wellhouse or zinc-tannin process. This is the same as the Burnettizing, only about two pounds of glue is added .to every one hundred pounds of water. This is allowed to stand under one hundred pounds pressure for about two and one-half hours, after which the solution is drawn off and a tannin solution forced in. A pressure of one hundred pounds is maintained for an hour, during which the tannin combines with the glue, forming a leathery water-proof coat Which permanently closes the pores of the wood, thus keeping the zinc inside and the water out. Cottonwood ties treated by the Wellhouse process lasted nine years; sweet gum, nine years; red oak, nine years; black oak, ten years; white cottonwood, eleven years; and Colorado pine, twelve years. These same ties without being treated would have lasted from three to five years. The time element in this process makes it valuable as it takes only about nine hours to treat a load. Another popular process is to heat green ties to a temperature of from 300 to 500 degrees under a pressure of one hundred seventy-fiw pounds per square inch. This can ses a chemical change in the sap, which turns it into a pre- servative. Still another process, Kyanizing, consists of steeping the ties in a solution of bi-chloride of mercury about one pound to eight or ten gal- lons of water. This hardens the wood. This