DescRIPTION oF A SPRING-BLOCK., 333 
the fhape of -her bottom might be: but would expend 
the force of the wind in heeling and flipping to leeward. 
if this is true, her failing muft be confiderably affifted by 
any means that fhall encreafe the active fpring of her rig- 
ging. For this purpofe I have contrived what I call a 
SPRING-BLOCK, to be applied to all fuch parts of the rig- 
ging as will admit of it with fafety and convenience, and 
where, its operation will be moft advantageous; but par- 
ticularly to the fheet-ropes, and, if practicable, to the dead. 
eyes in lieu of what are called the chains. 
Defcription. 
A, fig. 1, Is a block made in the ufual manner, having 
a ring or eye Bat oneend. C,is a fpiral {pring linked 
atone end to the hook D E and at the other to the ring. 
F, which is to be annexed by a ftaple to the timber-head, 
or by fome other means, to the place where it is to be 
applied, The fpring C, muft be of well tempered ftecl, 
and proportioned. in ftrength to the fervice it is to per- 
form. Within the cavity or pipe formed by the fpiral. 
{pring, there muft be a.chazn ofa fuitable ftrength called. 
a check-chain (reprefented feperate at G) conneéted 
by links to the rings D and F. When the fpiing 
is not. in aCtion this chain is flack; but when the. 
fpiral {pring is extended by the force of the wind as far as 
it can be without danger of injury; the cheek-chain muft 
then begin to bear, to prevent its further extenfion; and, 
if ftrong enough, will be an effectual fecurity againft. 
failure. 
Fig. 2. reprefents part of the gun-wale of a floop with 
the fpring-blocks in aGtion, one of them hooked to a ftaple 
in the timber-head, and the other to the corner of the jib. 
My expedtation is that a veffel thus furnifhed will be 
lefs liable to heel, that fhe will receive the impulfes of the. 
wind to better advantage, and fail with a more lively and: 
~ equable motion, than if rigged in the common way. 
Vires acquiret cedendo, N°, XLT, 
