(I £7) 
as to Heat dt Cold : Even fo nice, as that my being or not being 
in my Study I find to vary its hight fometiraes almoft a quarter 
of an inch,. 
My Bar ofcope , I call another Inftrument for eftimating the 
Weight or Prejjure of the Incumbent Air , confifting of a long 
Glafs-t-ubeoi about 4, foot in length, and about a quarter of an 
inch Bore: which tube (hermetically fealed at the one end)being 
filled with Quickfilver ( according to the Torricellian Experi- 
ments inverted, fo as to have the open end of it immerfed in 
Stagnant Quickfilver, contained in .a larger Glafs under it, ex- 
poled to the prefTureof the outward Air : Out of which open 
end (after fuch immerfion) the Quickfilver in the Tube being 
fuffered to run out, as much as it will, into the Stagnant Quick- 
filver, in which that mouth or open end is immerfed, there is 
wont to remain (as is commonly known to thofe acquainted 
with this Experiment ) a Cylinder of Quickfilver fufpended in 
the Tube, about 28, 29, or 30. inches high ; meafuring from the 
furface of the Stagnant Quickfilver perpendicularly ; ( but 
more or lefs, within fuch limits, according as the Weight or 
Prefiiire of the Air incumbent on the External Stagnant 
Quickfilver expofed to it , is greater or lefs ; ) leaving the up- 
per part of the Tube void. ( Both which Inftruments being 
the contrivance of the Honourable looker t Boyle , they are by 
him more particularly delcribed in his Phyfieo-Mechanicd Expe- 
riments touching the Air,Exper. 1 7. and 1 8. and in his Thermome - 
tried Difcourfes , premifed to his Hiftory of Cold .) 
"Now, according to both thefe Inftruments , having kept a 
daily By&ifler of Obfervations for more than a whole year ( la- 
ving when I have been for fome Ihort time abfent from home) 
I find my Notes for that day to be thefe^ 
January. 
Thermofcope. 
Barofcope. 
Day. Hour. 
19. 8. Morn, 
inches. 
T A 
1 4 16. 
inches. 
z* 
Hard froft, Clofe. 
4. Even. 
14 f. 
29 i 
Hardfroft. Cloudy. 
9* Even. 
14 i 
2 9 1 
Rain. Wind 
2©. 8. Morn. 
1 si- 
28 . . 
Sunlhine. Wind. 
So that, there being in the morning ( January 1 9 .) a hard f roif 
(which began the day before about 4, of the Clock in the after- 
noon 
