C 75 ) 
CONTINUATION EXPLANATION; 
OF THE PLATES. 
I have thought proper to be somewhat minute 
in describing the different parts of the Polygon 
Bui ; ding, which covers in the Pounding-Mill and 
Loft, as its complicated construction requires 
more correctness of workmanship than any of the 
other buildings. 
As the space is very considerable, it must of 
course have a support in the centre.—And here the 
first idea is, the making the arm work in a collar 
round the upright post ; which 1 however rejected, 
and adopted the mode, Plate V, Fig. 4, 5, 6,7, & S. 
Should occasion occur (which may never 
happen) the centre post may be removed by driv¬ 
ing out the key or wedge, and inclining the post 
a little on one side ; having previously secured the 
beam by temporary uprights. 
The Author has been obliged to make names 
for the different parts of the Iron-work ; which he 
has endeavoured to make as appropriate as he could. 
Plate V, Fig. 4, 5 , 6, 7? & 8. 
A—Represents the Pivot. 
M 
B. The 
