Waltham High School - Mirror Yearbook (Waltham, MA)

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4 WATCH CITY BULLETIN. its light almost equals that of the arc. One glance at this is quite enough. In this way heat is con- stantly poured into our brick box until the desired temperature is attained, or the bricks melt. One frequently finds on opening a furnace that half a brick has melted away into the bottom of the furn- ace. For very powerful currents, furnaces must be lined with carbon, as every other substance melts at this intense heat, and even carbon is slowly vapor- ized. The hardest and most durable rocks quickly melt. An electric furnace in action is sometimes an awe-inspiring spectacle. In making silicon, jets of flame six or eight inches long shoot from the furnace and light the room more brightly than if the sun were si' ' ' ' , . nr ows. These flames of l1n1ng1n at all the wi I the burning vapor of silicon are just as dazzling to look at as the sun itself. Many other metals also distil out of the furnace and burn, so that the room is often so filled with smoke that in spite of three windows, the door and ventilator in the roof all open, we are compelled to retreat out of doors. A curious danger attending work about an electric furnace is that of ftsunburnf' My wrists smart from it now. The eyes must be shielded from the direct light of the are or of burning silicon, etc The men who work in the furnace room have the appearance of coal heavers, for the finely ground carbon that is often used as a reducing agent, is blown out by the gases generated and settles ovei all persons and things indiscriminately. Yet in spite of the dirt and the disagreeble fumes I derive more pleasure from my experiments with the electric furnace than from any others. It is the exploration of a newly discovered continent in the world of chemistry. An experiment of a few days ago may l l l i l i u l l n l l l l v l give you an idea of the intense heat of the electric furnace. I melted some brass, intending to add something else to it, but the zinc distilled out and burned in the air, leaving the copper behind. This principle of fractional distillation was made use of in preparing the specimen of chromium now in the chemical laboratory of the high school. The sodium of the sodium dichromate, from which it was made, distilled away in a torrent of fumes. The way in which the furnace room was- set on fire a month ago shows even better the terrific heat of the furnace. This particular one consisted of a sheet iron box two and a half feetlong with a double layer of fire-brick all around and on the bottom. The current had been on all day, and was turned off at five P. M. There was no sign of fire then, nor at midnight when the last man left the furnace room, yet when the engineer came at seven the next morn- ing the woodwork in the room was about burned up. The heat within the furnace, had, during the night been conducted down through two layers of fire-brick and the five inches of the cement table top, and so set fire to the wooden supports beneath. Such heat as this is beyond the capacity of the high school equipment, but any experiments in electro- lysis, and even a small arc furnace, the equal of that with which Moisson began his world-renowned researches in electrochemistry, are within the range of the school outt, and I feel sure that any boy who once becomes interested in this fascinating field of experiment will not willingly give it up. VVith best wishes to my boys and girls of the High school, I am. Sincerely yours, OLIVER P. YVATTs.

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WATCH CITY BULLETIN. P3 Pl LETTER FROM WISCONSIN DEAR F1111-:Nns: I will gladly give the school through the columns of the VVATFII CITY BULLETIN a glimpse of my little corner in the University of Wisconsin. If you visit the Exposition at St. Louis this summer you can see the whole university there, in miniature. It may perhaps surprise you to learn that this heretofore unheard of institution is one of the great universities of the country, with nearly three thous- and students. ' Madison is about the size of XValtham, and is situated on a narrow strip of land between two lakes. The university grounds are upon an eleva- tion on the shore-of the larger lake, and so are very pleasantly located. There are iifteen large buildings not including the farm buildings of the college of agriculture. The iinest of these is the library build- ing, which is the best that I have yet seen at any institution of learning. My work here consists mainly of that newest of the sciences, electrochemistry. It is ditiicult to tell in a few words the scope of electrochemistry. It includes the principles involved in the manufacture and use of electric batteries, both primary and secondary, the theory of electroplating, and the electro-deposition of metals, this production by elec- trolysis of such substances as caustic soda, bleaching powder, potassium chlorate, aluminium, gold, and sodium, the purification of copper and gold, and the production in the electric furnace of phosphorus, manganese, calciufn carbide, carbarundum, graphite, artificial corundum, silicon and silicon alloys. It is a remarkable fact that silicon, the most abundant of all the elements, with the single exception of oxygen, an element which constitutes by weight one-fourth of the known earth, should have remained a chemical curiosity, seen only by a few even among chemists, until electrical methods made its isolation possible on a large scale. The next ten years will undoubt- edly see valuable applications of it. It is already 'finding a use in the casting of steel and copper. Al- tnougn the science of electrochemistry is scarcely fifteen years old, about high school age, it has already displaced the older, purely chemical Inethods in cer- tain industries, as the manufacture of phosphorus aluminium and potassium chlorate. Three fourths of the world's production of copper is now purilied by electroylsis, i.e. just electro-plating it out of solu- tion, with an annual saving of twenty million dollars in the gold and silver extracted, besides a great im- provement iii the copper by the removal of these impurities. The superior purity of electrolytic cop- per has greatly increased the etliciency of dynamos, motors, and all electrical machinery. Electrochemistry, besides producing some well known substances more cheaply and in greater purity than by any other means, has given us new substan- ces, like calcium, carbide and carborundum, which as far as we know, had never existed until made in the electric furnace. All important piece of experi- mental work has recently been completed here in the electro-chemical laboratory, in the production of pure iron by electrolysis. The properties of pure iron are unknown, for, if it has ever been obtained before, the amount has been too small to learn much about it. Prof. Burgess has made about five hun- dred pounds of it in the three years that he has been experimenting. There are two different principles involved in the manufacture of chemicals by means of electricity, that of electrolysis, in which materials are decom- posed by the agency of an electric current passed through them, just as when you send a current through salt dissolved in water, and secondly, that of the electric furnace, in which the only use of the electricity is to produce a higher temperature tabout 3800 C or 69700 FJ than can be obtained by any other means. At this great heat new combinations of the chemical elements take place, and several series of new compounds have been made. You would probably like to know what sort of thing this wonder- working electric furnace is. Those that I have been using are very simple in construc- tion. Imagine a box built of fire-brick with two large carbons projecting into it to carry the current. An electric furnace is only a magnified electric light shut up in the box to keep in the heat, and just as there are arc and incandescant lights, there are arc and resistance furnaces. In the former an arc is formed between the ends of the large carbons, and in the latter a rod of carbon several inches long and a quarter of an inch in diameter is set between the lai'ge carbons. VVhen a current of about two hun- di'ed amperes is turned on, this rod is heated until

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