NOTE 1.- The oz. stands for onza, the Spanish for ounce, and in cut. the c stands for centum, the Latin for one hundred, and wt for weight.

NOTE 2. The laws of most of the States, and common practice at the present time, make 25 pounds a quarter, as given in the table. But formerly, 28 pounds were allowed to make a quarter, 112 pounds a hundred, and 2240 pounds a ton, as is still the standard of the United States government in collecting duties at the custom-houses.

The term avoirdupois is from the French avoir du poid, signifying

NOTE 3. to have weight.

NOTE 4.

The standard avoirdupois pound of the United States is the weight, taken in the air, of 2770000 cubic inches of distilled water, at its maximum density, or when at a temperature of 39,83 degrees Fahrenheit, the barometer being at 30 inches. It is the same as the Imperial pound avoirdupois of Great Britain, which is the weight of 277274 cubic inches of distilled water at the temperature of 62 degrees.

10000

EXAMPLES.

1. In 165T. 13cwt. 3qr. 19lb. 14oz. how many ounces?

2. In 5302318 ounces how many tons?

3. If a load of hay weigh 3T. 16cwt. 2qr. 18lb., required

the weight in ounces.

4. In 122688 ounces how many tons?

5. Required the number of drams in 2T. 17cwt. 3qr. 161b. 15oz. 13dr.

6. In 1482749 drams how many tons?

7. What is the value of 7T. 17cwt. at 7 cents per pound? Ans. $1099.00. 8. What will 19cwt. 3qr. 20lb. of sugar cost at 9 cents per Ans. $179.55.

pound?

TROY OR MINT WEIGHT.

130. Troy or Mint Weight is the weight used in weighing gold, silver, jewels, and liquors; and in philosophical experi

NOTE 1. Troy weight was introduced into Europe from Cairo in Egypt, in the 12th century, and was first adopted in Troyes, a city in France, where great fairs were held, whence it may have had its name.

NOTE 2. - A grain or corn of wheat, gathered out of the middle of the ear, was the origin of all the weights used in England. Of these grains, 32, well dried, were to make one penny weight. But in later times it was thought sufficient to divide the same penny weight into 24 equal parts, still called grains, being the least weight now in use, from which the rest are computed. NOTE 3. Diamonds and other precious stones are weighed by what is called Diamond Weight, of which 16 parts make 1 grain; 4 grains, 1 carat. 1 grain Diamond Weight is equal to grains Troy, and 1 carat to 3 grains Troy. In weighing pearls, the pennyweight is divided into 30 grains instead of 24, so that 1 pearl grain is equal to grains Troy. The carat as a weight must not be confounded with the assay carat, a term whose use is to indicate a proportional part of a weight, as in expressing the fineness of gold, each carat means a twenty-fourth part of the entire mass used. Thus, pure gold is termed 24 carat gold, and gold that is not pure is termed 18 carat gold. 20 carat gold, &c., as its mass may be 18 twenty-fourths, 20 twenty-fourths, &c. pure gold. Each assay carat is subdivided into 4 assay grains, and each assay grain into 4 assay quarters.

NOTE 4.

The Troy pound, the standard unit of weight adopted by the United States Mint, is the same as the Imperial Troy pound of Great Britain, and is equal to the weight, taken in the air, of 2270 cubic inches of distilled water, at its maximum density, the barometer being at 30 inches.

EXAMPLES.

1. How many grains in 28lb. 11oz. 12pwt. 15gr. Troy?

2. In 166863 grains Troy how many pounds?

3. If a silver pitcher weigh 3lb. 10oz., what is its weight in grains?

4. How many pounds Troy in 22080 grains?

5. What is the value of 73lb. 11oz. of standard silver at $0.062 per pennyweight?

6. How many pounds of standard silver can be purchased for $1099.88, at the rate of $0.062 per penny weight?

7. A Californian has 57lb. 7oz. of pure gold. What is its value at $20.593 per ounce? Ans. $14229.901. 8. What is the value of a mass of standard gold weighing 191b. 6oz. 16pwt. at 93 cents per pennyweight?

Ans. $4367.28. 9. I have a lump of pure silver weighing 13lb. 9oz. What is its value at $1.385 per ounce ? Ans. $228.640.

APOTHECARIES' WEIGHT.

131. Apothecaries' Weight is used in mixing medical prescriptions.

NOTE 1. In this weight the pound, qunce, and grain are the same as in Troy Weight.

NOTE 2. Medicines are usually bought and sold by Avoirdupois Weight. NOTE 3. - In estimating the weight of fluids, 45 drops, or a common teaspoonful, make about 1 fluid dram; 2 common table-spoonfuls, about 1 fluid ounce; a wineglassful, about 11⁄2 fluid ounces; and a common teacupful, about 4 fluid ounces.

EXAMPLES.

1. In 23lb 93 03 29 13gr. how many grains?

2. In 136853 grains how many pounds?

3. How many scruples in 231b.?

4. How many pounds in 6624 scruples?

5. In 47b 03 03 19 19gr. how many grains? 6. In 270759 grains how many pounds?

7. A physician bought 1 pound of ipecacuanha for $1.80, and retailed it out in doses of 5 grains, at 12 cents each. How much did he get for it over the cost? Ans. $142.20.

AVOIRDUPOIS, TROY, AND APOTHECARIES' WEIGHT COм

PARED.

132. The relative value of the pound, and its subdivisions, of the several weights, in Troy grains, and in denominations of each other, is shown in the following

NOTE. To change a quantity from one weight to its equivalent in another weight, reduce the given quantity to Troy grains, and then find their value in denominations of the weight required.

EXAMPLES.

1. Change 131b. 6oz. Avoirdupois weight to Troy weight. 2. Change 16lb. 3oz. 1pwt. 1gr. Troy weight to Avoirdupois weight.

3. Change 31b. 8oz. 10pwt. to drams of Apothecaries' weight. Ans. 356dr.

4. Change 356 drams Apothecaries' weight to Troy weight. Ans. 3lb. 8oz. 10pwt.

5. An apothecary bought by Avoirdupois weight 2lb. 8oz. of quinine at $2.40 per ounce, which he retailed at 20 cents a scruple. What was his gain on the whole?

6. If I should buy by Avoirdupois weight 12lb. of opium a 37 cents per ounce, and sell it by Troy weight at 40 cents per ounce, should I gain or lose by so doing? Ans. Lose $ 2.

NOTE 1.-12 lines make 1 inch; 4 inches, 1 hand; 6 feet, 1 fathom; 120 fathoms, 1 cable length; 7 cable-lengths, 1 mile; of a degree of the circumference of the earth, 1 knot, or geographical mile, equal to 14 statute miles.

NOTE 2.- The yard adopted by the United States government as the standard unit of linear measure is the same as the imperial yard of Great Britain, which, as compared with a pendulum vibrating seconds in the latitude of London, the pendulum moving in a vacuum, at the level of the sea, and at the temperature of 62° Fahrenheit, should bear the proportion of 36 to 39,1393 inches. A metre, the unit of linear measure, as established by the French government, is equal to about 39.37 English inches.

100

NOTE 3. -The English statute mile is the same as that of the United States, but that of other countries differs in value from it; as the German short mile is equal to 6857 yards, or about 3 English miles; the German long mile, to 10125 yards, or about 5 English miles; the Prussian mile, to 8237 yards, or about 476 English miles; the Spanish common league, to 7416 yards, or about 4 English miles; the Spanish judicial league, to 4635 yards, or about 23 English miles.

360

NOTE 4. A degree of longitude is of any circle of latitude. As the circles of latitude diminish in length, the degrees of longitude vary in length under different parallels of latitude. Thus, under the equator, the length of a degree of longitude is about 69 statute miles; at 25° of latitude 62,7 miles; at 40° of latitude, 53 miles; at 42° of latitude, 51 miles; at 49° of latitude, 45 miles; at 60°, 347 miles.