ii7 
of floating Bodies, and the Stability of Ships. 
it is necessary that the position of the centre of gravity of 
the ship, and that of the part immersed, when the ship floats 
upright, should be known ; practical methods of mensu- 
ration are required, in both cases, to ascertain these points. 
When the angles of inclination are very small, to find the 
ship's stability, it is^ necessary to measure* the successive 
ordinates or breadths of the ship on a level with the wa- 
ter's surface, and when the angles of heeling are not limited, 
but are considered as being of any magnitude, the requisite 
mensurations are indeed more troublesome, but are not liable 
to more errors in execution than in the former case, when the 
angles are limited to those which are evanescent. 
The theorems for measuring the stability of ships, which 
are founded on assuming the angles of inclination from the 
position of equilibrium evanescent, explain, in the most sa- 
tisfactory manner, the principles on which the stability of 
ships, when heeled to small angles of inclination, is founded ; 
they also ascertain when ships or other bodies float on the 
water permanently in a given position of equilibrium, or over- 
set. But this can scarcely ever be an object of inquiry in respect 
of ships, which are always constructed so as to float upright, 
even before any ballast or lading has been added to them. 
Mons. Romme, in his valuable work on naval architecture, 
intituled L’ Art de la Marine, published at Paris in the year 
1787, informs his readers (p. 106), that the French ship of 
the line of 74 guns, called Le Scipion, was first fitted for sea 
at Rochfort in the year 1779. As soon as the ship was floated 
in deep water, a suspicion arose that she wanted stability ; to 
ascertain this point the guns were run out on one side, and 
drawn in at the other ; in consequence, the ship heeled 13 
* Chapman, chap. i. Clai rbois Architecture Navale, part. ii. sect. i. 
