Page:Philosophical Transactions - Volume 004.djvu/226



Dr. Beale in those Letters of his dated Decemb. 13. Decemb. 29., 1669, and Januar. 3, 1669/70.

Aving not look'd upon my Barometer a long time, I did by meer chance call my Eye on it upon Munday last, Decem. 13. 1669. about one of the Clock p. m.; and just then I saw the Quicksilver higher, than I dare positively affirme that it was ever since I had it in my custody, viz. since May 28. 1664. It was compleatly and apparently above half an inch more than thirty inches high. I called younger men to examine it over and over very carefully, by a measure, taken exactly from the standard-foot of London, both in Brass and in Box. They measured it often from that time, which was Munday, and late in the night of that day; then on Tuesday morning early; oft-times in the day, and late at Night: also some part of Wednesday. In all which time, when it was lowest, it was (as I said at first) compleatly 30½ inches; sometimes manifestly higher to the eigth [sic] or tenth part of a inch.

For this Baroscope I have two Glass-canes in one vessel of stagnant Quicksilver. They are of equal length, not fully two inches higher, than the Mercury ascended, and no Bolt-head to either of the Glasses. The one hath not been moved these two or three years, and hath a tincture of the Mercury on the empty top, as from the steams of the Mercury in some hot Summer; the other Glass was placed there about a year and an half agoe. This hath no tincture on the top. Both agreed in this Indication, as others affirme; but, to my Eye, in the latter Glass the Quicksilver seemed to be something higher.

The Weather was at first discovery very bright and clear: a gentle frost, by the Suns heat melting. The Air was very silent, no wind stirring, and the curious Wind-vane noting, that the wind was directly in the East all the first day (Decemb. 13;)