Page:Philosophical Transactions - Volume 024.djvu/158

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(1630)

open Cistern of the other. The Parts thus dispos'd, and the Stop-cock being turn'd, the Condens'd Air proceeds strongly thro the Swan-neck Pipe, which discharges it into the Horizontal Tube .G. Whose Currency so lessens the Pressure of the Atmosphere upon the Cisterns of the respective Barometers as to cause the Mercury to descend 2 inches at least. And 'tis observable, That that Barometer which is 3 foot distant from the Current Air is equally affected, and subsides parallel with the other. Likewise it is to be noted, that as the Current Air is weakned in its force, so doth the Weight of the Atmosphere again Encrease, and the Mercury in the Barometers gradually Ascend.

III. An Account of some Eclipses of the Sun and Moon, observed by Mr Tho. Brattle, at Cambridge, about four miles from Boston in New-England, whence the Difference of Longitude between Cambridge and London is determin'd, from an Observation made of one of them at London. By J. Hodgson.

On the 12th of June 1694. in the morning I went to the Colledge at Cambridge, about 4 miles from Boston, and observed, with the Brass Quadrant there, with Tellescopick Sights, the Rays of the Sun being transmitted through one of the said Sights, on a clean Paper, pasted on a plain piece of Board, and fastned at right angles at about a foot distance from the said Sight, on which Paper I had drawn a Circle between 2 and 3 Inches Diameter equal to the Suns disk, and within that several Concentrick Circles dividing the Diameter intoequal

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