go 6 Mr. Atwood's Disquisition oh 
ance of the water, which arises from the vessel's motion round 
its longer axis. 
The object of the preceding propositions, and inferences 
founded on them, has been rather to establish general prin- 
ciples, which may be of use in forming plans of construction, 
than to investigate what modes of construction are the most 
advantageous ; a discussion more extensive than would be con- 
sistent with the subject here proposed to be considered, which 
relates to the stability of vessels only. 
The practice of navigation requires the co-operation of many 
qualities in vessels, the laws and powers of which, considered 
as acting either separately or conjointly, it is the employment 
of theory to investigate. In respect to the construction of 
ships, it is obvious that no one of the component qualities can 
be regulated, without paying attention to all the others ; be- 
cause, by increasing or diminishing any of the powers of action, 
the others are commonly more or less influenced. It has been 
shewn, by the propositions demonstrated in these pages, that 
there are many practical methods by which the stability of 
vessels, at any given angle from the upright, may be aug- 
mented ; a circumstance which gives to the constructor great 
choice of means for regulating this power, according to the 
particular service for which the ship is designed ; for it is not 
every mode that wilbbe advantageous. The several varieties of 
form and adjustment by which stability is increased, may be 
so unskilfully combined, that, in consequence of the very 
means used to obtain that essential quality, either the ship 
shall not steer well, or shall drift too much to leeward, or shall 
be liable to sudden and irregular motions in rolling, by which 
