I 
SHIP BUILDING. 
.drawn in the half-breadth plan : thus, draw 
a straight line, parallel to, and as much be- 
low the upper side of the keel, in the sheer 
plan, as will admit of the depth of the keels 
a scale of feet and inches, by wliich the 
whole is to be drawn, and rather more than 
the main-half-breadth at 0, and this line 
will represent the middle line of the half- 
breadth plan, and is so called ; then square 
down upon this line the several perpendicu- 
lars from the sheer plan, and it will also 
there represent the several timbers as sec- 
tions crossing the timbers in the sheer plan 
at right angles. 
Then for the main half-breadth set up 
from the middle line, for S, 20 feet 4 in- 
ches; at O, 23 feet; at K, 23 feet 10 in- 
ches ; at F, S3 feet 11 inches ; at 0, 24 
feet; at 6, 23 feet 11| inches; at 12, 23 feet 
11 inches; at p, 23 feet 8 inches; at 24, 
22 feet 9 inches; at 30, 20 feet 10 inches; 
and at 36, 17 feet 9 inches. Draw a curve 
through these several half breadths, and the 
main half-breadth line will be described, 
except the fore aid after parts. Permit us 
here to observe, the best method for draw- 
ing this, and all other lines partaking of the 
nature of curves, is by elliptical moulds ; or 
what is better, when they are of any length, 
is by a thin pliable batten, confined down 
to the several spots, or dimensions, by 
square pieces of lead, about three or four 
ounces in weight ; because by this last me- 
thod the draughtsman has an opportunity of 
observing the fairness, or correctness, of the 
line before he draws it. Our readers will 
excuse this particular description, because 
it need not be repeated, as all lines hereafter 
are supposed to be drawn in the same man- 
ner. 
Now, to end the main halfbreadth for- 
ward proceed as follow : when the height of 
breadth cuts the fore part of the rabbit on 
the stem, square it down to the middle line 
of the half breadth plan, by taking its near- 
est distance from the adjoining perpendicu- 
lar, and setting off that distance in the same 
manner from the same perpendicular on 
the middle line in the half- breadth plan, and 
there square up a line ; then set up on it 10 
inches, the half-siding, or thickness, of the 
stem at that place; from the middle line 
then, with compasses opened to 4 inches, 
'the thickness of the plank of the bottom, 
sweep aft from the halfthickness of the 
stem an arch ; then with a radius equal 26 
feet 6 inches will finish the fore-part of the 
main half breadth line ; from the following 
centre draw a line at 4 feet 4 inches below 
and parallel to the middle line of the halt- 
breadth plan under timber O, and from 
timber O set forward 20 inches, and square 
it down to the line last drawn, and its inter- 
section will be the centre required ; then, 
with radius 26 feet 6 inches, sweep the seg- 
ment of a circle from timber S till it will in- 
tersect the back of the arch at the thickness 
of the bottom plank; thus the main half- 
breadth line is completed, except the after 
end, which must be finished hereafter. 
Next set off the half-breadth of the rising 
which limits the distance of the centres of 
the floor sweeps from the middle line on 
their respective heights in the body plan. 
Set up from the middle line of the halt- 
breadth plan, at timber K, 2 feet 9 inches ; 
at F, 7 teet 2 inches ; at 0, 8 feet 6 inches; 
at 6, 8 feet 5 inches; at 12, 7 feet 6 inches; 
at 18, 5 feet 3^ inches; and at 24, 8 inches ; 
then drawing a curve through those spots, 
the half breadth of the rising will be seen. 
We may now proceed to drawing the 
vertical curve appearance those several 
timbers will form below the lower height 
of breadth line in the body plan. Continue 
aft the upper edge of the rabbit of the keel 
line, and on it square up a line about 40 feet 
abaft the after perpendicular,and call this the 
middle line ; then at 24 feet distance, which 
is the main half-breadth at midships on each 
side the middle line, square up a side line; 
then, within the boundaries of 0, on the 
right hand, will be delineated the several 
timbers which compose the fore-body ; and 
within 0, on the left, those of the after- 
body. 
Now transfer the several heights of the 
lower height of breadth line from the sheer 
plan at and before 0, and set them up the 
side line in the fore-body plan, drawing ho- 
rizontal lines across at those heights to the 
middle line; then take the several main 
half-breadths from 0, and forward from the 
middle line of the half breadth plan, and set 
them off from the middle line on their cor- 
responding heights of breadth last drawn in 
the fore-body plan, and the utmost limits, 
or main breadth, of each timber will be 
shown. 
Now draw another curve in the half 
breadth plan which shall be the radius or 
length, whereby portions of circles are 
swept to form the shapd of the body some 
distance below the main breadth. Set up 
from the middle line at 0 in the half breadth 
plan 18 feet 9 inches ; at F, 1 8 feet ; at K, 17 
feet ; at 0, 15 feet 8 inches; at S, 18 feet 11 
inches ; at 6, 18 feet 9 inches; at 12, 18 feet 
