(Values for strength are those given in the Architects' and Builders' Pocket Book.)

Weight per cubic foot in pounds.

Average.

Weight per foot,

B. M. in pounds.

Average.

Safe Tensile Strength, per square inch.

Safe Crushing

Strength in pounds per square inch.

Safe Centre Load for

Beam 1 inch square and 1 foot long.*

Safe Shearing Strength with the

Grain, pounds per square inch.

Safe Crushing

Strength across the

Grain, pounds per square inch.

Chestnut..............

40

3.3

1,500

530

60

Hemlock................

30

2.5

1,200

450

55

70

200

Oak, white................

52

4.3

2,000

750

75

150

600

Pine, Georgia yellow............

43

3.6

2,000

1,000

100

120

500

Pine, Oregon............

36

3

1,800

750

90

100

400

Pine, Norway..................

36

3

1,600

700

70

90

400

Pine, white, Western............

30

2.5

1,500

625

65

80

200

Spruce................

36

3

1,800

625

70

90

250

Whitewood..............

35

3

1,200

500

65

.....

200

Slate...............

174

.....

........

.....

40

.......

......

Bluestone flagging...........

.....

......

.......

.......

25

.....

.........

Granite...............

167

......

......

850

18

.....

........

Limestone (Ind)................

158

.....

......

550

18

...

........

Marble..............

170

......

......

550

18

..

.........

Sandstone.................

139

...

......

450

12

.

.......

Cast iron.................

450

.....

2,600

13,500

308

7,000

......

Wrought iron....................

480

.......

10,000

10,000

666

7,500

12,000

Steel, medium...............

490

.....

12,500

13,000

888

7.500

12,000

" pin..............

...

.....

....

....

. .

7.500

12,000

" rivets..............

...

.......

....

....

..

7.500

15,000

* One-eighteenth of the " fibre strain " or safe " Modulus of Rupture."

†For full permanent loads, such as brick walls, etc., use only four-fifths of these values.