The School of Mines Quarterly, Volume 8Columbia University, 1887 - Chemistry |
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acid amount appears average bed-rock belt blue called carried cars cause cent centre chambers channel claim close coal College colors Columbia concentrator considerable construction contain continuous cost course cubic determined diameter direction distance effect engine equal experiments fact feet furnace give given glass gold gravel green ground heat inches increasing iron kind latter lead length less light load lower marks material means method miles mill mineral mines mountain nature necessary obtained ordinary original passed pipe plant position possible pounds practical present pressure produced quantity question reached river rock rope School shaft side specific square steel surface taken telescope tion train transmission treated tunnel usually valley washed weight yield York
Popular passages
Page 260 - Do I understand you, I said; and is your meaning that you teach the art of politics, and that you promise to make men good citizens? That, Socrates, is exactly the profession which I make. Then, I said, you do indeed possess a noble art, if there is no mistake about this; for I will freely confess to you, Protagoras, that I have a doubt whether this art is capable of being taught, and yet I know not how to disbelieve your assertion.
Page 317 - These plants prove beyond question that the Great Falls coal basin is of the same age with those that have been described north of the boundary line by Dr. George M. Dawson in what he has designated as the Kootanie series.
Page 227 - A body of mineral or mineral-bearing rock in the general mass of the mountain, so far as it may continue unbroken and without interruption, may be regarded as a lode whatever the boundaries may be. In the existence of such body, and to the extent of it, boundaries are implied. On the other hand, with well-defined boundaries, very slight evidence of ore within such boundaries will prove the existence of a lode. Such boundaries constitute a fissure, and if in such fissure ore is found, although at...
Page 135 - Then whatever parts either of the lens or of the polisher may be too high to form a spherical surface will be gradually worn down, thus securing the perfect sphericity of both. When the polishing is done by machinery, which is the custom in Europe, with large lenses, the polisher is slid back and forth over the lens by means of a crank attached to a revolving wheel. The polisher is at the same time slowly revolving around a pivot at its centre, which pivot the crank works into, and the glass below...
Page 181 - The diamond-bearing material at first excavated was a crumbling yellowish earth, which at a depth of about 50 feet became harder and darker, finally acquiring a slaty blue or dark green colour and a greasy feel, resembling certain varieties of serpentine. This is the wellknown " blue ground " of the diamond miners. It is exposed to the sun for a short time, when it readily disintegrates, and is then washed for its diamonds. This " blue ground " has now been penetrated to a depth of 600 feet, and...
Page 136 - ... the custom .in Europe with large lenses, the polisher is slid back and forth over the lens by means of a crank attached to a revolving wheel. The polisher is at the same time slowly revolving around a pivot at its centre, which pivot the crank works into, and the glass below it is slowly turned in an opposite direction. Thus the same effect is produced as in the other system. Those who practice this method claim that by thus using machinery the conditions of a uniform polish for every part of...
Page 227 - To determine whether a lode or vein exists, it is necessary to define those terms ; and, as to that, it is enough to say that a lode or vein is a body of mineral, or mineral-bearing rock, within defined boundaries in the general mass of the mountain. In this definition the elements are the body of mineral or mineral-bearing rock and the boundaries; with either of these things well established, very slight evidence may be accepted as to the existence of the other.
Page 338 - GG, and resting on shoulders of uprights, from the main timber of the mill. The motion, the water used, the grade, and the uphill travel should be regulated for every ore individually, but, once established, no further trouble will be experienced in the manipulation.
Page 182 - ... former sometimes surrounded by biotite, and the latter often partly altered to leucoxene. All these minerals lie in the serpentinic base, originally olivine. This rock appears to differ from any heretofore known, and may be described as a saxouite porphyry in which the base is not holocrystalline. The diamond-bearing portions often contain so many inclusions of shale as to resemble a breccia, and thus the lava passes by degrees into tuff or volcanic ash, which is also rich in diamonds, and is...
Page 113 - The hardness of these isomeric or allotropic species and their indifference to chemical agents increase with their condensation, or in other words vary inversely as their empirical equivalent volume, so that we here find a direct relation between chemical and physical properties.