The Practical Miner's Guide: Treatise on Mine Engineering, Comprisinga Set of Trigonometrical Tables Adapted to All Purposes of ... Dialing ... Also a Treatise on the Art and Practice of Assaying Metals ...

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Newton, 1858 - 191 σελίδες
 

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Σελίδα 185 - ... it all the drilled particles. On this principle I started to establish a new method of boring. The apparatus is composed of a hollow boring rod, formed of wrought iron tubes screwed end to end : the lower end of the hollow rod is armed with a perforating tool, suited to the character of the strata which have to be encountered. The diameter of the tool is larger than the diameter of the tubular rod, in order to form around it an annular space through which the water and the excavated material...
Σελίδα 135 - Then multiply the second and third terms together, and divide the product by the first term: the quotient will be the fourth term, or answer.
Σελίδα 172 - There is another class of injuries resulting from defective ventilation to which miners are exposed. The circumstances producing these injuries are slow in operation, and from their effects being disease, and not immediate and sudden death, their existtence has been little considered.
Σελίδα 75 - Add the logarithm of the given side to the sine of the angle opposite to the side required, and from the sum subtract the sine of the angle opposed to the given side; the remainder will be the logarithm of the side required. SYSTEM. There is much propriety in the remark, that " system is the handmaid of science," and the term may be considered as used in contradistinction to disorder, irregularity, or random.
Σελίδα 186 - ... the strata which have to be encountered. The diameter of the tool is larger than the diameter of the tubular rod, in order to form around it an annular space through which the water and the excavated material may rise up. The upper end of the hollow rod is connected with a forcepump by jointed or flexible tubes, which will follow the descending movement of the boring tube for an extent of some yards. This boring tube may be either worked by a rotary movement with a turning handle, or by percussion...
Σελίδα 172 - These effects are the result of an inadequate supply of air, which thus becomes vitiated and unfit for breathing, on account of its having lost its due proportion of oxygen, which is replaced by the formation of carbonic acid. This gas has its sources...
Σελίδα 79 - ... and on which an error of 4° would throw the end of the line nearly 9 feet too far either to the right or left. Should a dialler be called to do a job of this kind in the absence of a suitable instrument, he may accomplish it in the following manner : — Let him fix a cross-staff in such a position that, through one pair of sights, he can see the candle in the shaft, and in the line of the other pair, he has the dial fixed in the level, out of the way of the attraction ; consequently, the light...
Σελίδα 6 - ... every one who would use this work successfully should have some knowledge of decimated arithmetic; because he will have, in most cases, to multiply for the whole numbers, and take parts for the fraction of the fathom. For example : suppose the given side to be the hypothenuse, measuring 16 fathoms, 3 feet, and 6 inches, he will then have to take out the numbers opposite the given angle in the tables, and multiply them by 16, for the base and perpendicular respectively, then divide half the tabular...
Σελίδα 66 - AC in d and e; then take the distance ed in your compasses, and setting one foot on the brass pin at the beginning of the chords on your scale, observe how many degrees the other foot reaches to, which will be 4° 15
Σελίδα 172 - ... which has become vitiated and unfit for breathing, on account of its having lost its due proportion of oxygen, which is replaced by the formation of carbonic acid. This gas has its sources in respiration, the lights of the mine, the decomposition of small coal in the goaves (cavities of the roof), and of timber in the workings.

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