Improved Capstan and Windlass . 225 
(which all the other methods of effecting the same pur- 
pose before mentioned labour under,) can possibly take 
place, and of course the wear of the messenger occasion- 
ed thereby will he entirely avoided in it, while it per- 
forms its purpose more smoothly, equally, and with a 
less moving power than any of them. 
My method of preventing the necessity of surging con- 
sists in the simple addition of a second smaller barrel or 
capstan of less dimensions to the large one; beside 
which it is to be placed in a similar manner, and which 
need not in general exceed the size of a half-barrel cask. 
The coils of the messenger are to be passed alternately 
round the large capstan and this small barrel, but with 
their direction reversed on the different barrels, so that 
they may cross each other in the interval between the 
barrels, in order that they may have the more extensive 
contact with, and better gripe on each barrel. To keep 
the coils distinct, and prevent their touching each other 
in passing from one barrel to the other, projecting rings 
are fastened round each barrel, at a distance from each 
other equal to about two diameters of the messenger and 
the thickness of the ring. These rings should be so fixed 
on the two barrels, that those on one barrel should be ex- 
actly opposite the middle of the intervals between those 
on the other barrel : and this is the only circumstance, 
which requires any particular attention in the construc- 
tion of this capstan. The rings should project about as 
much as the cable or messenger from the barrels, which 
may be formed w ith whelps, and in every other respect, 
not before mentioned, in the usual manner for capstan 
barrels, only that I would recommend the whelps to be 
formed without any inclination inwards at the top, but to 
stand upright all round, so as to form the body of the cap- 
stan in the shape of a polygonal prism, if the intervals 
between the whelps are filled up, in order that the coils 
Vol. i. f f 
