and against 18, the fide of the fquare, in inches, on the girt line, is 40 on the flip, which is the answer in feet and fractional parts.

Ex. 2. Required the content, when the length is 19 feet, fide of the fquare 9 inches. Anf. 10 feet 8 inch. 6 pts. the length 24 feet, fide of the fquare 14 inches. Anf. 32 feet 8 inches.

Ex. 3

Ex. 4.23 feet, fide of the fquare 30 inches.

Anf. 146 feet 10 inch. 6 pts.

Ex. 5.14 feet, fide of the fquare 15 inches.

Anf. 17 feet 11 inches.

Ex. 6.22 feet, fide of the fquare 12 inches.

Anf. 22 feet 9 inches.

Ex. 7.-15% feet, fide of the fquare 10 inches.

Anf. 10 feet 6 inch. 4 pts. 8".

Ex. 8.24 feet, fide of the fquare 2 feet.

Anf. 96 feet 4 inches. Ex. 9.28 feet, fide of the fquare 11 inches.

Anf. 23 feet 10 inch. 7 pts. 1" 6". Ex. 10.10 feet, fide of the fquare 14 inches.

Anf. 12 feet 1 inch.

Ex. 11.6 feet, the fide of the fquare 3 feet.

Anf. 54 feet.

Ex. 12.8 feet, fide of the fquare 14 inches.

Anf. 10 feet 11 inches.

Squared timber, whofe breadth is greater than the thickness, may be truly caft up by the above rule with as much expedition. as with any other. Unfkillful measurers, however, generally add the breadth and thickness together, and they confider half their fum as the fide of the fquare, and work accordingly; but this method is falfe; and the greater the difference between the breadth and thicknefs is, the error thence refulting will be

the

the more confiderable; and in every cafe of this kind the refult is greater than the truth.

EXAMPLE I.

Required the folidity of a log whofe length is 19 feet, breadth 32, and thickness 20 inches.

By the Sliding rule.

Set the rule and flip even at the ends; and over against the

area

area of the bafe on the flip you have the fide of the fquare on the girt line; then the folidity is found, as above.

bafe being 30 inches by 20?

Ex. 2. How many cubic feet are in a log of wood 40 feet 6 inches long, the bafe being 32 inches by 20? Anf. 180 feet. Ex. 3. Required the content of a log of wood, whofe length is 13 feet, and bafe 10 inches by 8. Anf. 7 feet 4 in. 4 pts. Ex. 4. How many cubic feet are in a plank 12 feet long, t foot broad, and 6 inches thick? Anf. 16 feet 9 in. 3 pts. 10" Ex. 5. How many cubic feet are in a plank 20 feet long, the Anf. 83 feet 4 inches. Ex. 6. How many cubic feet are in a log, whofe length is feet 9 inches, the breadth being 12 inches by 5? Auf. 6 feet 6 inches 9 pts. Ex. 7. Required the folidity of a tree, 10 feet long, the bafe being 15 inches by 9. Anf. 9 feet 10 in. I prt. 6" Ex. 8. Required the content of a log 16 feet long, 30 inches broad, and 18 thick..

15

Anf. 50 feet. 9. Required the folidity of a plank 19 feet 3 inches long, 9. inches broad, and 6 inches thick. Anf. 7 feet 2 in. 7 pts. 6". Ex. 10. How many cubic feet are in a plank 17 feet long, Anf. 11 feet 6 in. 10 parts.

its bafe being 14 inches by 7?

Ex. 11. Required the content of a plank whofe length is 151 feet, breadth 10 inches, and thickness 8 inches.

Anf. 8 feet 7 inches 4 parts.

Ex. 12. Required the folidity of a plank whofe length is 19 Scet 10 inches, breadth 15 inches, and thickness 12 inches. Anf. 24 feet 9 inches 6 parts

PROBLEM III.

To find the folidity of round or unfquared timber.

RULE

RULE, common way.

Multiply the fquare of 4 of the circumference by the length, and the product will be the folidity.

EXAMPLE I.

Required the folidity of a tree whofe length is 32 feet, and

Set the length in feet on the flip to 12 on the girt line, aml over against the fide of the fquare, (which is 4 of the girt) on the girt line, you have the content on the flip.

Now, if we confider the tree a cylinder, its folidity may be found as follows.

The area of a circle, whofe circumference is 1, is .0795775; therefore,

By comparing the two methods above, we fee that the common way is 13 feet 7 inches 11 parts (which is nearly 4) lefs than the true quantity. It is ftrange that a method so absurd, and fo pernicious in its confequences, fhould ever be practised. The eafe with which it is performed is perhaps the only argument which can be alleged for using it.-The following rule will give the content extremely near the truth: It may be performed with equal eafe with the falfe one, and fhould on that account be univerfally used.

RULE.