C 343 3 
meter, was fixed in the Middle ofic. But what fur' 
prifed me hill more, and feemed to take off the 
Objection of the Draught of the Chimney, was. 
Jetting it once flay a little while againft the Bars, I 
found it Bill continue its Motion about its Axis in 
the fame Diredion. 
This put me upon makipg little Rings of Wire, 
to fix upon and move along the fupporting Tubes, fo 
as to flop the moving Tube at any Diftance from the 
Fire I pleafed. 
Stopp’d with thefe, the Motion of the Tube about 
its Axis ftill continued. 
Defirous to try what would be the Effed in or 
near an upright Pofture, I made the Pin at one End 
of my Tube reft upon a China Plate, that at the other 
Turn in a filver Socket (that carried my Pencil) fixed 
in an horizontal Arm of Wood, but fo as I could 
flip it up and down, to adapt it to the Length of 
of the Tube. Here I found, that if the Tube lean’d 
to my Right hand, (which was the Cafe of Mr. 
Ormes Tubes before his Fire) the Motion was from 
Eaft to Weft j but if they leaned to my Left, the 
Motion was from Weft to Eaft 5 and the nearer I 
could get to the perfedly upright Pofture, the lefs 
the Motion feem’d to be either Way. 
I now proceeded to place my Tube horizontally 
upon a glafs Plane (a large Fragment of a Coach-fide 
Window Glafs). The Tube, inftead of moving to- 
wards the Fire, moved from it, and about its Axis, 
in a contrary Diredion to what it had done before, 
Obferving that this glafs Plane was broader at one 
End than the other, and that the Rotation back- 
wards was more fenfible when the narrower End was 
X x 2 towards 
