<4i ) 
I. An Account of an Inftrament or Machine for 
changing the Air of the Room of fickfPeople 
in a little Time , by either drawing out the foul 
Air , or forcing in f refit Air ; or doing both fuc~ 
ce/fvely , without opening Doors or Windows. 
N. B. The Model of this Machine, made by a Scale 
of an Inch to a Foot , -was jhewn the Royal So- 
ciety the thirteenth TAay of June, 1734. By 
TAr. J. T. Defaguliers, F.R.S. (Vide Tab.) 
Fig. 1. Eprefents a Cafe DE CB, containing 
rC a Wheel of 7 Feet in Diameter, and 
1 Foot thick ; being a cylindrical 
Box, divided into iz Cavities by Partitions direfted 
from the Circumference towards the Center, but 
wanting 9 Inches of reaching the Center, being 
open towards the Center, and alfo -towards the Cir- 
cumference, and only clos’d at the Circumference 
by the Cafe, in which the Wheel turns by means of 
an Handle fix’d to its Axis A, which Axis turns in 
rwo Iron Forks, or half concave Cylinders of Bell- 
Metal, fuch as A, fix’d to the upright Timber or 
Standard A E. • 
From the Middle of the Cafe on the other Side 
behind A, there comes out a Trunk or fquare Pipe, 
which we call the Sucking-Pipe ; which is continued 
quite to the upper Part of the fick Perfon’s Room, 
whether it be near or far from the Place where the 
Machine flands, in an upper or lower Story, above 
or below the Machine. There is a circular Hole 
in one of the circular Planes of the Machine of 
E 18 Inches 
