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Art. 14. To find tic tonnage of a sliip.

NULE. Multipis tne.cngth of the keel by the breadth of tne beam, and that pro uct by the depth of the hold, and divide the last product bris, and the quotient is the tunnage.

Suppose a sivip72 feet by the keel, and 94 feet by the beam, and 12 feet decp; what is the tonnage ?

72794x19---953-218,2+-ions. Ans.

HOLE U. Multiply the lengin of the keel by the breadth of the beam, and that product by half the breadth of the beam, and divide by 95.

A ship 84 feet by the keel, 28 feet by the beam; what is the tonnage ?

84X28X14---95=350,29 tons. Ans. RT. 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 weignt of its anchor.

EXAMPLE.

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 6x6x6:2fcut. : : 12x12x19: 18cut. Ans.

2. If a 12 inch cable require an anchor of 18 cwt. wirat must the circumference of a cuble be, for an anchor of 24 cwt. ? cict.

cul. As 13 : 12x12x12 :: 2,25 : 016 3216=6 Ans. ÅRT. 16. Having the dimensions of two similar built

ships of a different capacity, with the burthen of one of tim, to find the burden of the other,

212.

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 ker; I demand the burther of another ship, whose keel is !: 9 feet long?

T.cut.qrs.li:. As 75x75x75: 500 :: 100x100x100 :711 2009:

DUODECIMALS,

OR

CROSS MULTIPLICATION, Is

a rulo made use of by workmen and artificers in ca:“. ing up the contents of their werk.

RULE. 1. Under the multiplicand write the corresponding denominations of the multiplier.

2. Multiply cach terun into the inultiplicand, beginni: at the lowest, by the highest lenomination in the mu! plier, and write the result of each under its respect: terin; vbserving to carry an unit for every 12, from ea lower clenomination to its next superior.

3. In the same manner multiply all the multiplica: ; by the inches, or second denomination, in the multipli and sei the result of each term one place removed to : right band of those in the maltiplicann..

4. Do the same with the seconds in the multiplier, ting the result of each tern two places to the right käis of those in the multiplicand, &c.

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TEET, INCHES AND SECONDS.

F. I. Multiply 9 8 6 By 7 9 S

[tiplier. 67 11

=prod. by the feet in the mul7 3 4 6 "=ditto by the inches.

2 5 1 6=ditto by the seconds.

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How many square feet in a board 16 feet 9 inches long, and 2 feet 5 inclies wide ? By Duodecimals.

liy Tecimais.
F. 1.
16 9

16 9=16,75 feet.
2 S

2 3 2,95

33 6
4. 2 S

8975 $950 S350

Ans. S7 & S

Ans. 37,6875--S7 8 9 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.

How

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

7 ft. 6in.=7,5 and 4 ft. 2 in.=4,167 and 2 ft. S in= 2,25; then, 7,5X4,167=51,2525 x2,25=70,318125 solid feet, Aris.

But loads of wood are commonly estimated by the foots 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 cords which is still called 4 feet of wood.

By measuring the breadth and heighth 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 ligi. By Duodecimals. By Decimcls. F.in,

F. 3 9

3,75 2 6

2,5

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9 4 6 9,375

F. in. ans. 4 8 S 4,6875=4 81, or half a cord and

81 inches over. the foregoing method is concise and easy to those who are well requainted with Duodecimals, but the following Table will give the content of any load or wood, by inspection only, sufficienty emag For common practico; whicb will be found very convenient

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A TABLEW Dreath, Treight, and Content. Breaslth. || Height in feet.

Taches. ft. in. 1121314111213 4 | 5 | 6171819 110111 2 6 15 30145 61 24 6 7 9/10111112|14|

7 1631 47 624 S!4 6 8 9 10 12 13 14 8 16:32 48|641|S

8 9 11 12 13 15 9 || 17 35 496613146 89/11 12/14/15 10 17 94 51 68 21514

9 10111311416 11 18 351531701 S4 6 7 | 9|10|12|13|15|16 3 0 1856.5472

8 9111|12|14|15|17 1 195756174

8 911 1914 16:17 2 1915857170

8 10 11 13 14 1617 3 191395978

8 1 10 11 13 15 16 18 4 120/40/60/80

8 10 12/13 15 17118) 5 1|21|41162 821 2567 8 10 |12|14161719) 6 1214263/94! 24

9 11 10/14/16/18/19) 7 129143164 862 4

9 11 13 14 16 18 20 8 1294460881 214 9 11 13 15 17|18|201 9 1284568190!

7 9 11 13 15 17 1921 10 12346,69,92

4

9 12 15 15 17 19121 11 2347709412 416 8 10 12 14 16 18 20 22 4 O 1:24:487319612416 8 10 12 14 16|18|20|22

TO USE THE FOREGOING TABLE. First measure thc breadth and hcight of your load to the nearest average inch; then find the breadth in the left hand column of the table; ther more 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 cor. tent 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 be added by inspection.

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EXAMPLES.

1. Admit a load of wood is 3 feet 4 inches wide, and 2 feet 10 inches high; required the content.--Thus, against 3 st

. 4 inches, and under % feet, stands 40 inches; and under 10 inches at top, stands 17 inches: then 40 to 17357 true content in inches, which divide by 12 gives 4 feet g inches, the answer.

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

Thus, with breadth 3 feet ( inches, and under 2 feet

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