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Art. 14. To find the tonage of a ship.

RULE. Multiply the length of the keel by the breadth of the beam, and that product by the depth of the hold, and divide the last product by 95, and the quotient is the tonege.

EXAMPLE.

Supposc a ship 72 feet by the keel, and 24 feet by the beam, and 12 feet deep; what is the tonage ?

72x24x12:95=218,2 + tons. Ans.

RULE II. Multiply the length of the keel by the breadth of the bcam, and that product by half the breadth of the beam. and divide by 95.

EXAMPLE.

A ship 84 feet by the kecl, 28 feet by the beam; what is the tonnage ? 84X28X14;95=350,29 tons

Ans. ART. 15. From the proof of any cable, to find the

strength of another.

RULE.
The strength of cables, and consequently the weights of
their anchors, are as the cube of their peripheries.
Therefore ; As the cube of the periphery of any cable,

Is to the weight of its anchor ;
So is the cube of the periphery of any other cable,
To the weight of its anchor.

EXAMPLES. 1. If a cable 6 inches about, require an anchor of 2 est. of what weight must an anchor be for a 12 inch cable?

As 6x6x6 : 2 cwt. : : 12x12x12 : 18cwt. Ans.

2. If a 12 inch cable require an anchor of 18 cwt. what must the circumference of a cable be, for an anchor of 2 cwt. ? coot.

rut.

in. As 18 : 12x12x12 . 2,25 : 216216-6 ans. Art. 16. Having the dimensions of two similar built

ships of a different capacity, with the burthen of one of them, to find the biuthan of the over

RULE. The burthens of similar built ships are to each other, as the cubes of their like dimensions.

EXAMPLE. If a ship of 300 tons burthen be 75 feet long in the keel, I demand the larthen of another ship, whose keel is 105 feet long?

T. ciot. qrs. lh. As 75x75x75 : 300 : : 100X100X100 : 711 2 0 24-4

DUODECIMALS,

OR

CROSS MULTIPLICATION, Isa

S a rule made use of by workmen anıt artificers in cast: ing up the contents of their work.

RULE. 1. Under the multiplicand write the corresponding doo nominations of the multiplier.

2. Multiply each term into the multiplicand, beginning at the lowest, by the highest denomination in the multiplier, and write the result of each under its respective term : observing to carry an unit for every 12, from each lower denomination to its next superior.

3. In the same manner multiply all the multiplicand by the inches, or second denomination, in the multiplier, and set the result of each term one place removed to the riglu hand of those in the multiplicand.

4. To the same with the seconds in the multiplier, setting the result of each term two places to the right hand of those in the multiplicand, &c.

EXAMPLES.
F. 1. F. ]. F. I. F. I.
Multiply 73

4 6 97 Ву

3 9 5 8

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FEET, INCHES, AND SECONDE.

F. ] Multiply 3 8 6 By 7 9 3

[multiplier AT 11 6

e=prod. by the fect in the 3 4 6 18!! == ditto by the iuches. 2 5 1 6 =ditto by the seconds.

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llow many square feet in a board 15 feet 5 inches long, and 2 feet 3 inches wide ? By Duodecimals.

By Decima's.
I.

Fi 1.
9

16 9=16,75 feet. 2 3

23=2,23

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1

TO MEASURE LOADS OF WOOD.

RULE. Multiply the length by the breadth, and the product by the depth or height, which will give the content in solid feet; of which 64 make half a cord, and 128 a cord.

EXAMPLE.

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How many solid feet are contained in a load of wood, 7 feet 6 inches long, 4 feet 2 inches wide, and 2 feet 3 inches high?

7 ft. 6 in.=7,5 and 4 ft. 2 in. =4,167 and 2 ft. 3 in. 2,25; then, 7,5 x 4,167=31,2525X2,25=70,318125 solid feet, Ans.

But loads of wood are commonly estimat?d by the foot, allowing the load to be 8 feet long, 4 feet wide, and then 2 seet high will make half a cord, which is called 4 feet of wood; but if the breadth of the load be less than 4 feety its height must be increased so as to make half a cord, which is still called 4 feet of wood.

By measuring the breadth and height of the load, the content may be found hy the following

RULE. Multi ly the breadth by the height and half the product will be the content in feet and inches.

EXAMPLE.

Required the content of a load of wood which is 3 feet 9 inches wide and 2 feet 6 inches high. By Duodecimals. By Decimals.

F.in.
3 9
2

2,5

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9

9,375

1. in. 8 3

4,687524 81, or half a card

and 8 inches over. The forening method is corese and easy to those who are well ac. palikti with Duodecinuls, but the following Table will gire the cor!!!! of any load of word, by inspectica only, sufficiently exact for com will graciice; thirh will be ficku ven conversioni

A TABLE of Breadth, Height, and Content. Breadih. Height in fett.

Inches ft. in.

12314142 3141516171819110111 2 6 115 30 45,60 2 4 5

3110 1/12 14 17 1631 471621! 1 3

1 56 8 9 10 12 13 14 8 16 32 48 64 11314 5 | 7 8 91111213/15 9 1733966 314 6 ng 8 9111214115 10 ||17|34 51681 3 4617 9 10111113 14 16 11

18 35 53 702 34 1 6 7 9 110 12 13 15 16 3 0 18 36 54 72 2 3 5 6 8 911111214115117

1 1937156 741 2 3 5 6 8 9111112 14 16 17 2 1938|5776

6 8 10 11 13 14 16/17 3 1939:5317811 315 7 811011 13 15 16 18

2010/60801 35mg 81101213 15 17 18 5 2114116282 3 5! 7 3 |1012 14 16 17|19 6 21.42,63841 | 4 | 5 9 111 112 14 16 18 19 7 224364186| 2 4 5 7 9 11 13 14 16 18 20 8 2944.66.88 214 617 9 11 13 15 17 18/20) 9 | 23j45 68 90: 214167 3.11 13 15 17 19 21 10 23,46 69 92 | 24617 9 1213115 17 1921

11 23 47 70 94 2 468 10 12 14 16 18 20 22 4 0 1124|48|72|96|52| 41618 10 12 14 16 18 20 22

TO USE THE FOREGOING TABLE. First measure the breadth and height of your load to the nearest ave. raze inch; then find the breadth in the left hand column of the table; then move to the right on the same line till you come under the height in feet, and you will have the content in inches, answering the feet, to which add the content of the inches on the right and divide the sum by 12, and you will have the true content of the load in feet and inches.

Norg.--The contents answering the inches being always small, may be added by inspection.

EXAMPLES

1 Admit a load of woca 13 3 feet 4 inches wide, and 2 feet 10 inches bigh; required the content.-

Thus, against 3 feet 4 inches, and under 2 feet, stands 40 inches; and under 10 inches at top, stands 17 inches . then 10+17557 true content in inches, which divide by 12 gives 4 feet 9 inches, the answer.

2. The breadth being 3 feet, and height 2 feet 8 inches; required the content.

Thus, with breadth 3 feet 0 inches, and under 2 feet atop, standa 38

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