Page:An introduction to linear drawing.djvu/104

 ﻿Example 1. A cask is 31 inches in diameter at the bung, 28 at the base or head, and its length is 54 inches. What is its capacity ?

The radius of the base is ... 14 The radius of the bung is ... 15,5

14	times 14 multiplied by 34 • ........616

15	times 15,5 multiplied by do..........755

Repeated........755

Amount, neglecting fractions, 2126

Multiply this by 18, which is a third of the length, and you have the answer, 38268 cubick inches.

There are 231 cubick inches in a gallon. To find then how many gallons the above cask contains, divide its contents by 231.

2.	Required the contents of a cask whose diameter at the bung is 38,6 inches, at the head or base 33,4 and whose length is 63,9 inches. Ans. 68546,753 cub. ¡tic

3.	Required the contents of a cask whose circumfer- ence at the bung is 90 inches, at the base 80 inches, and whose length is 48 inches. Ans.284115 cub.in.1229 gals.

Problem III. To find the volume or solid contents of a pyramid or a cone.

Rule. Multiply the base by the height, and take a third of the product.

Example 1. A loaf of sugar has a base 4,8 inches in diameter, and is 12,3 inches in height.. What are its contents ?

Find the contents of the base by multiplying the ra- dius or half diameter 2,4 by 2,4, and the product by 34, (Sect. I. Prob. 5.) Multiply the latter product by the height 12,3 and divide tfie product by 3 to find a third of it, which will be the answer. Ans. 74,21 cub.in*