Page:History of the Royal Society.djvu/198

 the Center of which, the Index is turned round: The Beginning or Standard of which Degree of Rotation, should be that, to which the Index points, when the Beard, being throughly wet, or covered with Water, is quite unwreathed, and becomes strait. But because of the Smalness of this Part of of the Oat, the Cod of a wild Vetch may be used instead of it, which will be a much larger Index, and will be altogether as sensible of the Changes of the Air.

"4.The Degrees of Pressure in the Air; which may be several Ways observed, but best of all with an Instrument with Quick-silver, contrived so, as either by means of Water, or an Index, it may sensibly exhibit the minute Variations of that Action.

"5.The Constitution and Face of the Sky or Heavens; and this is best done by the Eye; here should be observed, whether the Sky be clear or clouded; and if clouded, after what Manner; whether with high Exhalations or great white Clouds, or dark thick ones. Whether those Clouds afford Fogs or Mists or Sleet, or Rain, or Snow, &c. Whether the under side of those Clouds be flat or waved and irregular, as I have often seen before Thunder, Which way they drive, whether all one Way, or some one way, some another, and whether any of these be the same with the Wind that Blows below; the Colour and Face of the Sky at the rising and setting of the Sun and Moon; what Haloes or Rings may happen to encompass those Luminaries, their Bigness, Form and Number.

"6.What Effects are produc'd upon other Bodies: As what Aches and Distempers in the Bodies of Men; what Diseases are most rife, as Colds, Rh