[ * 5 * ] ' 
It is certainly definable, that the fails of windmills 
jfhould be as fhort as poffible j but at the fame time 
it is equally definable, that the quantity of cloth 
fhould be the lead; that may be, to avoid damage by 
fudden fqualls of wind. The bed; ftrudture, there- 
fore, for large mills, is that where the quantity of 
cloth is the greateft, in a given circle, that can be : 
on this condition, that the effe< 5 t holds out in pro- 
portion to the quantity of cloth j for otherwife the 
effedl can be augmented in a given degree by a leffer 
increafe of cloth upon a larger radius, than would 
be required, if the cloth was increafed upon the fame 
radius. The mod; ufeful figure therefore for practice, 
is that of N®. 9. or 10. as has been experienced upon 
feveral mills in iarge. 
Table 
