A Textbook on Mining Engineering, Volume 8

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International Text Book Company, 1900
 

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Page 16 - Operations with Fractions A) To change a mixed number to an improper fraction, simply multiply the whole number by the denominator of the fraction and add the numerator.
Page 18 - When the denominators are not alike we know that the units are divided into -unequal parts, so before adding them we must find a common denominator for the denominators of all the fractions. Reduce the fractions to fractions having this common denominator, add the numerators and write the sum over the common denominator. In this case, the least common denominator, or the least number that will contain all the denominators, is 16; hence, we must reduce all these fractions to sixteenths and then add...
Page 154 - ... specific gravity — as applied to wood, the ratio of the ovendry weight of a sample to the weight of a volume of water equal to the volume of the sample at some specific moisture content, as green, air-dry, or ovendry.
Page 4 - In the multiplication of whole numbers, place the multiplier under the multiplicand, and multiply each term of the multiplicand by each term of the multiplier, writing the right-hand figure of each product obtained under the term of the multiplier which produces it.
Page 119 - Law. — The temperature remaining the same, the volume of a given quantity of gas varies inversely as the pressure.
Page 8 - ... the direction of the current in the conductor is reversed, the north pole will point towards the east. Since, in this example, the north pole of the needle tends to point towards the east, the current must be flowing from the north to the south.
Page 19 - When mixed numbers and whole numbers are to be added, add the fractional parts of the mixed numbers separately, and if the resulting fraction is an improper fraction, reduce it to a whole or mixed number. Next, add all the whole numbers, including the one obtained from the addition of the fractional parts, and annex to their sum the fraction of the mixed number obtained from reducing the improper fraction.
Page 47 - Andre sums up the requirements of a good percussive machine rock-drill as follows: 1. It should be simple in construction and strong in every part. 2. It should -consist of few parts, and especially of few moving parts. 3. It should be as light as possible, consistent with strength. 4. It should occupy as little space as possible. 5. The striking part should be of relatively great weight, "and should strike the rock directly. 6. No parts except the piston and bit should be subject to violent shocks.
Page 122 - W= weight of body at the surface; w = weight of a body at a given distance above or below the surface ; d= distance between the center of the earth and the center of the body ; R = radius of the earth = 4,000 miles.
Page 11 - No claim shall extend more than three hundred feet on each side of the middle of the vein at the surface...

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