CAR
95
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f,. 6r ’ an< ^ na 'l or bolt them to the curve: to prevent them0t » extending before they are fixed, nail a temporary piecethe ° S8 two extremities, and set them in their places;n w hen the other ribs are nailed against them, they will
remain firm, and this without much trouble of construction.—In this operation, the kerfs must run in lines perpen-dicular to the base, otherwise they will not bend to theplan.
A TABLE FOR THE SCANTLINGS OF TIMBER.
A Proportion for Timbers for small Buildings.
A Proportion for Timbers for large Buildings.
Bearing Posts of Fir
Bearing Posts of Oak
Bearing Posts of Fir
Bearing Posts of Oak
Height
Scantling
Height
Scantling
Height
Scantling
Height
Scantling
if 8 feet
4
in. square
if 10 feet
6 in.square
if 8 feet
5
m.square
if 8 feet
8
in. square
10
5
12
8
12
8
12
12
12
6
14
10
16
10
16
16
Girders of Fir
Girders of Oak
Girders of Fir
Girders of Oak
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
it 16 feet
8
in. by 11
if 16 feet
10
in. by 13
if 10 feet
94
n. by 13
if 16 feet
12
in by 14
20
10
124
20
12
14
20
12
14
20
15
' 15
24
12
14
24
14
15
24
134
15
24
1
18
16
Joists of Fir
Joists of Oak
Joists of Fir
Joists of Oak
Bearin
o*
Scantling
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
if U test
5
in. by 24
if 6 feet
5
in. by 3
if 6 feet
5 in. by 3
if 6 feet
6
in. by 3
9
64
2J
9
n
3
9
74
3
9
9
3
12
8
24
12
10
3
12
10
3
12
12
3
Bridgings of Fir
Bridgings of Oak
Bridgings of Fir
Bridgings of Oak
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
it 0 feet
4
in. by 24
if 6 feet
4
in. by 3
if 6 feet
4 in. by 3
if 6 feet
5
in. by 3i
8
5
n
8
64
3
8
54
3
8
64
34
10
6
3
10
7
3
10
7
3
10
8
34
Small Rafters of Fir
Small Rafters of Oak
Small Rafters of Fir
Small Rafters of Oak
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
Bearing
Scantling
» 8 feet
34 in. by 2J
if 8 feet
44 in. by 3
if 8 feet
4£ in. by 3
if 8 feet
54
in. by 3
10
44
24
10
64
3
10
54
3
10
7
3
12
6 *
24
12
64
3
12
04
3
12
9
3
Beams of Fir, or Ties
Beams of Oak, or Ties
Beams of Fir, or
Ties
Beams of Oak, or Ties
Length
Scantling
Length
Scantling
Length
Scantling
Length
Scantling
u 30 feet
6
in. by 7
if 30 feet
7
in. by 8
if 30 feet
7 in. by 8
if 30 feet
8
iu. by 9
45
9
8 J
45
10
114
45
10
114
45
11
124
60
12
11
60
13
15
60
13
15
60
14
16
Principal Rafters of Fir
Principal Rafters of Oak
Principal Rafters of Fir
Principal Rafters of Oak
Scantling
Scantling
Scantling
Scantling
Length
Top
Bottom
Length
Top
Bottom
Length
Top
Bottom
Length
Top
Bottom
if 24 ft.
5 in. & 6
6 in. & 7
if 24 ft.
7 in. & 8
8 in. & 9
if 24 ft.
7 in. & 8
8 in. & 9
if 24 ft.
8 in. & 9
9in.&10
36
6 i
8
8 10
36
8
9
9 104
36
8
9
9 104
36
9
10
10 12
48
8
10
10 12
48
9
10
10 12
48
9
10
10 12
48
10
12
12 14
hati^ a ° u gh this table seems so plain as to need no expla-that not be amis8 t0 observe some particulars, such
a gai n aU binding or strong joists ought to be half as thickl hr ee j 8 common joists ; that is, if a common joist be given4 half , thick, a binding-joist should be four inches and“ 0^ Uc h> although the same depth.lf > Partit^ r ' e a l ao ’ tllat conveniency do not allow of poststh e sid° nS 1>eing S( l uare > in su ch cases, multiply the squarelf it b e - e th e posts, as here given, by itself: for instance,r 0 nSe que 1 X i mclleS S( l uare > th en as six times six is thirty-six,' 4 d so ntl y to keep this post nearly to the same strength,Ni 0 ?r ber that sllal1 agree thereto; as suppose the! 4 c he s t) 10 be four inches thick, then let your post be nineJJ'ifir, tli e ether way, so that nine times four is thirty-six,parly tli ® Sa “ e as six times six; so that the strength is0r th
' lI >e M Same ' although being equal in its squares is besti “ l 1 os ts ength-
* hol() g0 tbe height of two or three stories, need
, Vlt h a ,. Us proportion, because at every floor it will meetadmit o wo a i.: ~ u
thf V ldnUt a P ost was required of thirty feet high,8 height there were three stories, two of ten feet,
and one of eight. Look for posts of fir of ten feet high, theirscantling is five inches square, i. e. twenty-five square inches ;which double for the two stories.
“ And take also that of eight feet high, being four inchessquare, i. e. sixteen square inches, all which being addedtogether, make sixty-four square inches; so that such a postwould be eight inches square. On occasion it may be lessenedin each story as it rises.
“ I do not insist that the scantlings of timber ought to beexactly as by this table is expressed, but may be varied insome respects, as the workmen shall see fit; the reason ofits being inserted, is in consideration of the scantlings oftimber, as formerly settled by act of parliament, gn^. which,if compared, will prove the necessity and use of this table.
“ As to plates on walls, or bressummers to support walls,I do not find they can come into any regular proportion, asthe rest do, therefore must be left t® discretion.
“ And as I have herein described a great variety of theprincipal things requisite to be known by every carpenter, Ishall conclude this part with my wishes that it may prove asuseful as my earnest endeavours have been to make it so.”