X24 Gen. Roy’s Account of 
From the elevation it will be perceived, that nine or ten inches 
of the under extremities of the cheeks were cut off, fo as to 
permit the bottom itfelf to reft on the irons. This conftruc- 
tion of the coffers was found to anfwer very well, that is to 
lay, they were, confidering their length, not fo heavy as to 
be unmanageable, at the fame time that by their general figure, 
and particularly the depth of the cheeks, they were entirely 
prevented from warping. 
In addition to the fifteen coffers, juft now defcribed, a six- 
teenth, not reprefented in the plate, was afterwards prepared 
at Hythe by Lieut. Fiddes, to be ufed occafionally, when the 
end of one chain, and commencement of another, coincided 
with a deep ditch or one of the fewers full of water, and 
where of courfe it would have been extremely difficult, if not 
impoffible, to have fixed fteadily the group of three pofts in 
the ufual manner. In this coffer^ there was a double or falle 
bottom, with grooves adapted for the purpofe ; and the brafs 
fcale, pulley, &e. were removed from the irons, and placed oil 
this bottom a 
Art. IV. Apparatus of caft iron , &c. for the ends of the Chain . 
By referring to the plate, where the feveral parts of the ap- 
paratus for the extremities of the chain are reprefented in plan* 
and feftion, by a fcale equal to one- fourth of their real dimen- 
lions, it will appear, that the caft-iron pieces were of two dif- 
ferent forms, one long, and the other fliort ; but both applied 
in the fame manner, on the ferrules binding the tops of the 
pofts, as has been already mentioned. Of the long kind there 
were in all fifteen or fixteen, that is to fay, one for each poft 
in a length of three chains. Each iron had two clamps on its 
c under 
