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Art. 14.–To find the tonnage 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 tonnage.

EXAMPLE.

Suppose a ship 72 feet by the keel, and 24 feet by the beam and '12 feet deep; what is the tonnage ?

72x21x12:95=218,2+tons. Ans.

RULE II.

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

EXAMPLE,

A ship 84 feet by the keel, 28 feet by the beam ; what is Die tonnage ? 84 x 28 x 14:95=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 periplcrics, 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 21 cwt. of what weight must an anchor be for a 12 inch cable?

As 6 x6x6 : 21 cwt. : : 12 x 12 x 12 : 18 cut. 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 21 cwt. ? cwt.

cwt. As 18 : 12 x 12 x 12 : : 2,25 : 216 216=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 burthen of the other.

in.

3

EXAMPLE.

OR

RULE.
The burthens of similar built ships are to each other, at

Makiply the cubes of their like dimensions.

By If a ship of 300 tons birthen be 75 feet long in the kcel,

Product, I demand the burthen of another ship, whose keel is 100 feet long?

To cut.qrs. lb.
As 75X75X75:300 : : 100 x 100 x 100 :711 2 0 24+ Multiply

By
DUODECIMALS,

Product,
CROSS MULTIPLICATION,
IS a rule made use of by workmen and artificers in cast

F. ing up the contents of their work.

Multiply 9 RULE.

By

7 1. Under the mulplicand write the corresponding deno

67 minations 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; ob

75 serving to carry an unit for every 12, from eache lower donomination to its next superior.

3. In the same manner multiply all the multiplicand ky Multiply 7 the inches, or second denomination, in the multiplier, and By set the result of each term one place removed to the righ: hand of those in the multiplicand.

Product, 58 4. Do 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.

By Duro

F. F.I. F.I. F.I. F.I.

16 Multiply 7 3

7 5

4 6 97 By

3 9 58 97

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and 2 feet

EXAMPLES.

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Ans. 37

Product, 33 2.9

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FEET, INCHES AND SECONDS.

F. I.
Multiply 9 8 6
Ву 7 93

(tiplior 67 II 6 =prod. by the feet in the muts 7 3 4 6

ditto by the inches. 2 5 1 6 Editto by the seconds.

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How many square feet in a board 16 feet 9 inches longt and 2 feet 3 inches wide ? By Duodecimals.

By Decimals.
F. l.

F. 1.
16 9

16 9-16,75 feet. 2 3

2 3-2,25 33 6

8375 4 23

3350

3350
Ans. 37 8 3

F. I.
Ans, 37,6876-87 88
T

A TABL

Ilow many

TO MEASURE LOADS OF WOOD. Rule.-Multiply the length by the breadth, and the product by the doptk or height, which will give the content in solid feet'; of which 64 make half a cord, and 128 a cord.

EXAMPLE

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 st. 3 in= 2.25 ; then, 7,5 x 4,167=31,2525 X 2,25=70,318125 solid feet, Ans.

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

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

RULE.-Multiply 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

3,75
26

2,5

Breadth. \\Heigh Ifl. in. 1/2 2 6 1530

1631 8 1632 9 17:33 10 1734

11 ||18/35 30.1330

1 1937 2 193€ 3!1939 4 20140 5 2141 6 1214 ny 22.43 8 12244 9 1123 10 |1234

11 (23147 4 0 24142

TO

1875 750

First measure the Înch; then find the to the right on the will have the conten of the inches on the true content of the

Note --The cont added by inspection

1 10 6

9 4 6

9,375

F. in.
Ans 4 8 3 4,6875=4 87 or half a cord and El

inches over. The foregoing method is concise and easy to those who are well acquainted with Duodecimals, but the following table will give ho content of any load of wood, by inspection only, sufficiently exact for common prustico; which will be found ver Tonvenient.

1. Admit a load required the conten Thus

, against 31 der 10 inches at to inches, which divid

%. The breadth t lant.

'Thus, will brea

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A TABLE of Breadth, Height, and Contens,
Breadth. || Height in feet.

Inches.
ft. in. l 1 | 2 | 3 | 4 1 2 3 4 5 6 7 8 9 10 11
2 6 15 30 45.60 124567 910111214

| 161314762!! 1) 3 4 5 6 8 9 10 12 13 14 8 16 32 48 64 1 3 4 5 7 8 9 11 12 13 15 9

1733 49 661 1 31 41 7 8 9/11/12 14 15 10 ||17 34:51 68|| 2 3 4 6 7 9 10 11 13/14/16 11

1835 53 70! 2 3 4 6 7 9 10 12 13!15 16 3 0 || 18/36 5472 2 3 5 6 81 911 12 14 15 17 1 1937

1937 5074|| 2 3 6 81 9 11 12 14 16/17 2 | 19385776 3 5 6 8 10 11 13 14 16 17! 3 1939 59 78|| 2 3 5 7 8110 11 13 15 16 18 4 ||20.40 60 80 3 5 7 8 10 12 13 15 17 18 5 21 41 62 82|| 2 3 5 7 8 10 12 14 16 17|19 6 ||21426384 2 4 5 7 9 11 12 14 16 18 19 na ||22 43 6486| 2 51 7 9 11 13 14 16 18 20 8 122 4466,88 46 64 7 9 11 13 15 17 18 20/ 9 ||23 45 6890 4 6 6 7 9 11 13 15 17 1921 10 ||23 46 69 92 4 6 7 9 12 13 15 17 19 21

il ||23|47 70 94|| 2 41 6 8 10 12 14 16 18 20 22 4 0 24 487296|| 21 41 6 8 10 12 14 16 18 20/22

TO USE THE FOREGOING TABLE, First measure the breadth and height of your load to the nearest average 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.

Note. The contents answering the inches being always small, may oe added by inspection.

EXAMPLES 1. Admit a load of wood is 3 feet 4 inches wide, and 2 feet 10 inches nigb, 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 40+17=57, 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 con lept.

Thus, with breadth 8 foet 0 inches, and under 2 feet ajan, stands og

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