V 
V. Observation of an extraordinary Height of 
the Barometer , December 21. 1721. By 
Mr. George Graham., Watchmaker , F. R. $, 
Jan. nth, 1711. 
T TPON Thnrfday the 21ft of December laft, ob- 
I J ferving the Barometer much higher than ufu- 
al ; chat Evening, between Seven and Eight a Clock, 
I fill d a Tube with very clean Quick-filver, and found 
the Height a little to exceed 30,75 Inches. By Eight 
the next Morning, a Wheel-Barometer, which hung 
in the fame Room, had rifen One tenth of an Inch 
higher than it was the Night before, when the Expe- 
riment was made ; at Ten a Clock, One fifth of an 
Inch more : At which Time it was at the higheft, be- 
ing a little above 30,8- Inches ; for about Twelve at 
Noon it was fenfibly lower, and continued falling all 
the reft of the Day. 
When the lower End of the Tube was firft immers'd 
in the Ciftern, the Quick-filver for fome Time adher’d 
to thfe Crown of the Glafs , but upon fhaking, it fell 
to the Height above-mentiond. 
VI. A 
