r 64 3 



think, of five or fix guineas 5 one on the larger fcale, 

 caufed by the increafed fubftance of the metal and 

 the CKtra fize and length of the pipes, might amount 

 to twenty, which in either is under four-pence per 

 quarter on the firft cargo; and as they will lart: many 

 years if well painted, and when not in ufe taken to 

 pieces and put carefully by, I flatter myfclf it is an 

 experiment well worth trial ; particularly, if a pre- 

 mium be offered to the Ihip-owner, who by means 

 of fuch machine imports his corn pure and untainted 

 from a didant land. 



QByEcrioyr. made to the fuppofed EffeEl of the Venti- 

 lator^ over-n:kd, it is boped^ by the confideratiom 

 •which follow them. 



\JIS I "^HE. holes pierced in the tin tubes which arc 

 ■*- to lie under the corn, feem capable of if- 

 fuing (efpecially if an effort be made upon them) a 

 much larger quantity of air, than the forcing-pump 

 will fupply in a given time. Confequently a given 

 quantity of thefe holes, under a given preffure, will 

 be capable of iffuing the whole fupply of air with- 

 out any affiftance from the remainder. 



idly. If thefe pofitions are jufl, it mufl: happen, 

 that if a cargo of corn be unequally circumflanced 



ia 



