Improved Capstan and Windlass * 
^ creeping into the service* more expensive* and much 
“ worse than one lately exploded.’* 
As you and the members of the Committee have seen 
the letter* I imagine further attestation needless relative 
to it. 
I request you will mention* that all friction of the re- 
volutions of the cable (or messenger) in passing each 
other between the barrels of the capstan* must be effec- 
tually prevented by the whole thickness of one of the 
rings that passes betwixt each crossing. I add this be- 
cause one of the gentlemen of the Committee wished to 
be informed on this point. I am* &c. 
J. W Boswell. 
Sir— In obedience to your intimation* that a written 
explanation of the advantages to be obtained by the use 
of capstans made according to the model* which I laid 
before the Society for the Encouragement of Arts* &c. 
would be acceptable* I send the following* which I hope 
will make the subject sufficiently clear. 
As few but mariners understand the manner in which 
cables are hauled aboard in large ships* it will probably 
render the object of my capstan more manifest* to give 
some account of this operation. — Cables above a certain 
diameter are too inflexible* to admit of being coiled round 
a capstan ; in ships where cables of so large dimensions 
are necessary* a smaller cable is employed for this pur- 
pose* which is called the messenger * the two ends of 
which are made fast together so as to form an endless 
rope* which* as the capstan is turned about, revolves 
round it in unceasing succession* passing on its course to 
the head of the ship* and again returning to the capstan. 
To this returning part of the messenger* the great cable 
is made fast by a number of small ropes* called nippers* 
placed at regular intervals ; these nippers are applied, as 
