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Thermometers, Barometer, Hygrosopcopes.

These Observations being thought very considerable as well as curious, 'tis hoped, that those who have convenience, will give encouragement and assistance for the making of them; and withall oblige the publick by imparting, what they shall have observed of this kind: The Publisher intending, that when ever such observations shall be communicated to him he will give notice of it to the publick, and take care of the improvement thereof to the best use and advantage, A Pattern of the Table, proposed to be made for observing the Tides, is intended to be published the next opportunity, God permitting.

An Account
Of several Books lately published
.

1. Johannis Hevelii DESCRIPTION COMETÆ, Anno Æra Christianæ MDCLXV, exorti unà cum MANTISSA Prodromi Cometici, Observationes omnes prioris COMETÆ MDCLIV, exiisque genuinum motum accuratè deductum, cum Notis & Animadversionibus, exhibens.

This Book (as the Title it self intimates) undertakes two things. First, To give an Account of the Second of the two late Comets, which appeared, when the other was scarce extinct; Concerning which, the Author doth, from the Observations made by himself with a Sextant of 6 foot, and divided into minutes and seconds, assign both its true place (as well in respect of the Ecliptick as the Æquator) and its proper motion: Adding a fair Delineation of its Course, together with the genuine Representations of its Head and Train, in each day of its apparition; and subjoining a General Description and Discourse of some of the more notable Phenomena thereof. It was first seen at Dantzick by the Watchmen, the 5th of April st. n. 1665. and then observed by the Author from April 6. about 11/2. of the Clock in the morning, till April 20. at 3. in the morning. During which time, it went with a reasonable velocity; making 46deg. in its Orb, according to the Order of the Signes moving from the Breast of Pegasus, towards the Head of Andromeda, and the Left Horn of Aries; having, as 'tis presumed, taken its rise from above Sagittary, and run through the Breast of Antinous under Aquila, and the Dolphin, to the said Pegasus; and so on, as is already expressed.

The Head of it is in the Book described of a Colour like that of Jupiter, all along much brighter than that of the former Comet, though of somewhat less magnitude; having in its middle onely one round, but very bright and big Kernel or Speck, resplendent like Gold, and encompassed with another more dilute and seemingly uniform matter: its Tail being at first, about 17 deg. and afterwards 20. and sometimes 25. deg. long, and divaricated towards the End.

Next, it is observed, that though this Star did afterwards slacken its pace, yet it retained the vividness of its Colour, both of the Head and Train; the Head especially, keeping at the time as well of the last observations, as of the

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