(b.) When numbers expressing values in sterling money are used, the character £ marks the pounds, s. the shillings, d. the pence, and qr. the farthings. Illustration. 27 pounds, 18 shillings, 5 pence, and 3 farthings, may £ s. d. qrs. 18 5 3. Farthings Thus, 7 d. 3 qrs. = be written thus: 28£, 18 s. 5 d. 3 qrs.; or thus: 27 (c.) The coin representing the pound is called the sovereign. Its value in United States money varies from four dollars and eighty-three cents to four dollars and eighty-six cents, but is usually about four dollars and eighty-four cents. There are several other coins used in England, of which we will mention only two, viz., the guinea, or twenty-one shilling piece, and the crown, or five-shilling piece. 34. Avoirdupois Weight. (a) Almost all articles, except gold, silver, and jewels, are weighed by what is called Avoirdupois Weight. (b.) The abbreviations made use of in this weight are T. for ton, cwt. for hundred weight, qr. for quarter, lb. for pound, oz. for ounce, and dr. for dram. For example, 5 T. 17 cwt. 3 qr. 13 lb. 8 oz. 7 dr. T. cwt. qr. lb. oz. dr. 5 17 3 13 8 7 5 tons, 17 hundred weight, 3 quarters, 13 pounds, 8 ounces, and 7 drams. (c.) Formerly the quarter was reckoned at 28 pounds, the hundred weight at 112 pounds, and the ton at 2240 pounds, and they are so reckoned at the present time in Great Britain as well as in the standard of the United States government. Most of the states of the Union have, however, passed laws fixing the values as in the table, and they are almost always so reckoned by merchants in buying and selling. 35. Troy Weight. (a.) The weight used in weighing gold, silver, and precious stones is called Troy Weight. This weight is also used in philosophical experiments. (b.) In this weight, lb. stands for pound, oz. for ounce, dwt. for pennyweight, and gr. for grain. Illustration. 13 pounds, 7 ounces, 18 pennyweights, 23 grains, may lb. oz. dwt. gr. be expressed thus: 13 lb. 7 oz. 18 dwt. 23 gr.; or thus: 13 7 18 23. (c.) The "carat," which equals four grains, is used in weighing diamonds. The term carat is also used in stating the fineness of gold, and means the twenty-fourth part of any weight of gold or gold alloy. Pure gold is "24 carats fine." Gold is 22 carats fine when 22 of it is pure gold and is alloy. 2 24 36. Apothecaries' Weight. (a.) The weight used in compounding or mixing medicines is called Apothecaries' Weight. Physicians write their prescriptions in this weight, but medicines are bought and sold by Avoirdupois Weight. TABLE OF APOTHECARIES' WEIGHT. 20 grains = 1 scruple. 3 scruples 8 drams 1 dram. 1 ounce. 12 ounces = 1 pound. To mark the denominations of this weight, we use the following characters, viz.: H for pound, 3 for ounce, 3 for dram, for scruple, and gr. for grain. For example: 5 b 63 43 29 17 grs., would be read as 5 pounds. 6 ounces, 4 drams, 2 scruples, and 17 grains. 37. Comparison of Troy, Avoirdupois, and Apothecaries' Weights. (a.) The only difference between Troy Weight and Apothecaries' Weight is, that in the former the ounce is divided into pennyweights and grains, while in the latter it is divided into drams, scruples, and grains. The pound, ounce, and grain are the same in both weights. (b.) The value of denominations of the same name ir. Avoirdupois' and Troy Weights differs very materially, as may be seen from the following table, which shows the value in Troy grains of each denomination we have given in the preceding tables of weights. (c.) From the above table we should find by calculation that 144 lb. Av. 175 lb. Tr., 175 oz. Tr. and 192 oz. Av. Therefore, 1 lb. Av. = 31 172 or 14 lb. T`., and 1 oz. Av. = 131⁄2 oz. Tr. (d.) Which is the heavier, and why, 1. A pound of gold or a pound of feathers? 4. An ounce of gold or an ounce of feathers? 38. Long Measure. (a.) Distances in any direction are measured by Long Measure. (b.) In this measure, le. stands for league, m. for mile, fur. for furlong, rd. for rod, yd. for yard, ft. for foot, and in. for inches. (c.) Surveyors usually measure distances by means of a chain 4 rods in length, called Gunter's chain, the Surveyor's chain. This chain contains 100 equal links; 25 links will, therefore, equal 1 rod, and 1 link will equal 7 39. Cloth Measure. inches. (a.) This measure is used for measuring cloth, ribbons, &c. (b) In this measure, yd. stands for yard, qr. for quarter, and na. for nail. (c.) The yard and inch are the same in length as the yard and in Long Measure 40. Square Measure. (a.) Square Measure is used for measuring surfaces. As true ideas of the nature of the right angle, rectangle, and square are essential to a just appreciation of this measure, we insert the following definitions and illustrations, leaving it with the teacher to give such others as he may deem necessary. (b.) When two lines meet at a paint, their difference in direction is called the angle of the two lines. The point where they meet is called the vertex of the angle. B (c.) In this figure, the lines marked B A and B C form an angle whos verte is at B. In reading an angle, the letter at the vertex is always made the middle one. The angle in Fig. 1 may be read either as the angle A B C, or as the angle C B A. (d.) In this figure there are two angles, viz., D B A and A B C. The first is the difference in direction of the two lines A B and D B, and the second is the difference in direction of the twc lines A B and B C. It is evident that the first angle is larger than the second. (e.) When the two angles formed by one straight line meeting another are equal to each other, they are called right angles, and the two lines are said to be perpendicular to each other FIG. 3. D B (f) Suppose that the straight line D B should so meet the straight line A Cas to make the adjacent angles A B D and D B C equal to each other; then A B D and D B C will each of them be right angles, and D B and C A C will be perpendicular to each other. (g.) An angle greater than a right angle is called an obtuse (blunt) angle, and one less than a right angle is called an acute (sharp) angle. |