SHIP BUILDING. 
earefully represented by a drawing, called 
the sheer draught, tiie construction of 
■which, with its several lines, &c. we shall en- 
deavour as familiarly as possible to describe 
to our readers. 
The principal dimensions, as they are ge- 
nerally termed, must be first decided upon, 
and they are the following, viz. 
The length at the gun-deck in ships of 
war, or distance between the extreme per- 
pendiculars in merchant ships. 
The extreme breadth, which is the thick- 
ness of the bottom plank on each side, 
added to the moulded breadth, or broadest 
part of the ship in midships. 
Length of the keel for tonnage, which re- 
sults from the extreme breadth and a length 
liereafter given. 
Depth in hold, which must be always 
yegulated by the properties required of the 
vessel. 
Burthen in tons, resulting from the ex- 
treme breadth and length of the keel for 
tonnage, being multiplied into each other 
by a rule given hereafter. 
Now these are called the principal di- 
mensions, which we will endeavour to 
describe, with their concomitant circum- 
stances, in their above order i and, first, the 
length on the gun-deck ; this in ships of war 
must ever contain sufficient distance be- 
tween the perpendiculars for all the ports, 
and room between each port for working 
the guns, and what may be required at the 
extremities, such as the manger at the fore- 
part, and abaft room for the after-port, to 
come clear of the wing transom knee, &c. 
It will also appear evident that the distance 
between each port in the clear must con- 
tain space sufficient for two frame timbers 
and the filling timbers between, and the 
room or openings between the timbers. 
Thus we find by established practice the 
distance between, and size of the ports, in 
the following class of ships in the navy, are as 
follow : 
1 
Guns. 
Sloop'. 
1 On the main deck, viz. ; 
110 
98 
74 
50 
36 
18 
1 Foreside of the foremost port 
1 abaft the foremost perpendi 
Ft. In. 
Ft. In, 
Ft. In. 
Ft. 
!n. 
Ft. In. 
Ft. 
;n. 
11 
6 
11 
4 
7 
0 
17 
6 
10 
6 
6 
9 
I Aft-side of the after port afore 
the after perpendicular 
13 
0 
15 
6 
16 
6 
to 
0 
4 
9 
12 
0 
Ports deep 
2 
9 
g 
9 
2 
8 
2 
7 
2 
6 
2 
2 
fore and aft 
3 
6 
3 
5 
3 
5 
3 
4 
3 
0 
2, 
5 
In distance from port to port*... 
r 
9 
7 
9 
7 
6 
7 
10 
7 
0 
6 
11 
In number on each side 
16 
15 
15 
11 
F3 
10 
Thus we may find the most ap- 
proved length on the gun- 
193 
0 
188 
8 
180 
C 
146 
C 
137 
c 
110 
0 
1 
Tonnage of Merchant Ships. 
1257 
1000 
818 
544 
441 
329 
• 
Foreside of the foremost port 
abaft the foremost perpendi- 
Ft. In. 
Ft, In. 
Ft. In. 
Ft. In. 
Ft. In. 
Ft. In; 
cular 
22 6 
22 0 
22 0 
14 6 
31 0 
6 6 
Aft-side of the after port afore 
Foreside 
1 the after perpendicular 
14 6 
13 6 
13 4 
12 6 
■well. 
8 4 
1 Ports deep 
2 2 
2 S 
2 2 
2 0 
2 0 
1 10 
fore and aft 
2 5 
2 5 
2 5 
2 4 
2 -1 
2 o 
In distance from port to port*... 
8 3 
8 3 
8 3 
7 6 
6 0 
7 6 
In number on each side 
13 
12 
12 
11 
10 
10 
Thus we may find the most ap- 
1 
proved length between the per- 
K 
peiidiculars of merchant ships 
165 6 
159 0 
146 0 
124 9 
120 9 
103 4 1 
* Sometimes an additional timber is added between the ports at the gang-way, to 
make it the more convenient for the steps, .Sjc. 
