We have the following rule for performing

COMPOUND ADDITION.

Place the numbers so that those of the same denomination may stand under each other; placing those of the highest denomination on the left, and proceeding orderly towards the right till you have written the lowest denomination.

Begin with the right hand column, and find the sum as in simple addition, carrying as many to the next higher denomination from this sum, as this sum contains units of the next higher denomination, and proceed in every respect as in simple addition, except in carrying to the higher denomination, and keeping each denomination separate from the rest.

Before performing on compound numbers, you must learn the tables of weights and measures, which I will give you with an example annexed to each.

24 grains

TROY WEIGHT.

make 1 penny-weight, marked grs. pwt.

20 penny-weights

12 ounces

By this weight are weighed jewels, gold, silver, corn, bread and liquors.

In this example I begin with the right hand column, and find its sum is 45, which is 45 grains, and because 24 grains make 1 penny-weight, I seek how many times 24 is contained in 45, and find it is once and 21 over; I set down 21, and carry 1 to the next higher denomination, which is pennyweights. I then find the amount of the column of pennyweights, and seek how many units of the next higher denomination are contained in it, and find it

is once and 15 over. next column, and proceed in this manner with all the other parts. Numbers in all the other weights and measures are added in the same manner, observing to carry, in all cases, from the lower to the next higher denomination, according to the quantum, which it takes of the lower to make one of the next higher.

I set down 15 and carry 1 to the

By this weight are weighed all things of a coarse or drossy nature; such as butter, cheese, flesh, grocery wares, and all metals except gold and silver.

The diameter of a Winchester bushel is 18 inches, and its depth 8 inches. One galion, dry measure, contains 268 cubic inches.

By this measure are measured salt, lead, 'ore, oysters, corn and other dry goods.

The ale gallon contains 282 cubic inches. In London the ale firkin contains 8 gallons, and the beer firkin 9; the other measures being in the same proportion.

By this measure, brandy, spirits, perry, cider, mead, vinegar and oil are measured.

231 cubic inches make a gallon, and 10 gallons make an anchor.

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60 geographical miles, or

69 statute miles,

1 degree, nearly, deg.or.

360 degrees the circumference of the whole earth.

60 seconds 60 minutes

24 hours

TIME.

make 1 minute, marked s. or ". m.or'.

1 hour,

1 day,

The following rules are occasionally useful, but not so much used as those already given.

Apothecaries use this weight in compounding their medicines; but they buy and sell their drugs by Avoirdupois weight. Apothecaries is the same as Troy weight, having only some different divisions.

40 poles

make 1 square foot.

1 yard.

1 pole.

1 rood.

4 roods, or 160 rods, or 4340 yds, 1 acre.