The following Table is slightly modified from one given by Mr. Lawford in a paper read before the Society of Engineers.1

Approximate cost, weight, and safe load of each floor undermentioned - for 12 feet bearing.

Constructers.

Cost per Square Yard.

Weight per Square Foot.

Safe Load per Square Foot.

Excluding Joists.

Including Joists.

Excluding Joists.

Including Joists.

Arched.

S.

d.

S.

d.

lbs.

lbs.

cwt.

Dennett ...............

6

9

9

3

50

54

2

Doulton ...............

6

6

9

0

30

34

2

Wilkinson.................

6

0

7

6

50

52

2

Flat.

Dawnay ...............

7

0

40

2

Gardner .................

7

0

46

2

Homan and Rodgers

7

0

35

2

Lindsay, a.................

7

0

44

2

Evans and Swain.........

10

6

No joists required.

20

No joists required.

7