Page:Philosophical Transactions - Volume 004.djvu/233

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in the morning, to 7¼, and did not all that day come so high as 8. inches. Which being so much lower, than ever it had been in any of the precedent years of my observation, though it may in part be attributed to the dis-spiriting of the liquor, y et principally to the extremity of the Cold.

It hath ever since been rising, (but with some descent in the night-time,) and was on January 1. when the frost seem'd first to relent, somewhat higher than 9; and is this day, Januar. 7, about 13½. The Baroscope at 29; but for some days before, it was about 28¾, (the weather having been windy and rainy;) and so it was in the frost, about Decemb. 25, but then continued to rise till about Januar. 2. to 29⅛; but had been Decemb. 13. at 30⅛; which is the highest, I have ever known it in my Baroscope; 27⅞ being the lowest, that I have ever observed it in, (Octob. 26. 166;) the most usual hight being about 29, or somewhat higher.

But, though mine have been very rarely, and but very little, above 30, or lower than 28, (reckoning from the surface of the stagnant Quicksilver;) Yet in other places (according to the difference of Airs) it may by others have been found either higher or lower: and so likewise, according as the Quick-silver, at the first filling of the inverted Tube, was more or less cleansed of Air. For, a very little Air, left in the Quick-silver, and undiscernable to the Eye, will, when it gets free of it, and remains in the voyd space above the Quick-silver, sensibly depress the Quick-silver: And in the mean time, (before it so gets free) will, upon heat of weather, make it swell.