Mr. _Boyle_._

It having been already intimated (_Num. 8 of Phil. Transact._ p. 140. 141.)
that divers _Philosophers_ aime, among other things, at the Composing of a
good Natural History, to superstruct, in time, a _Solid_ and _Useful_
Philosophy upon; and it being of no slight importance, to be furnisht with
pertinent Heads, for the direction of Inquirers; that lately named
_Benefactour to Experimental Philosophy_, has been pleased to communicate,
for the ends abovesaid, the following _Articles_, which (as himself did
signifie) belong to one of his _Essays_ of the unpublisht part of the
_Usefulness of Nat. and Experimen. Philosophy_.

But first he premises, that what follows, is design'd only to point at the
more _General_ heads of Inquiry, which the proposer ignores not to be
Divers of them very comprehensive, in so much, that about some of the
_Subordinate_ subjects, perhaps too, not the most fertile, he has drawn up
_Articles_ of inquisition about particulars, that take up near as much
room, as what is here to be deliver'd of this matter.

The _Heads_ themselves follow;

The things, to be observ'd in such a History, may be variously (and almost
at pleasure) divided: As, into _Supraterraneous, Terrestrial_, and
_Subterraneous_; and otherwise: but we will at present distinguish them
into those things, that respect the _Heavens_, or concern the _Air_, the
_Water_, or the _Earth_.

1. To the _First_ sort of Particulars, belong the Longitude and Latitude of
the Place (that being of moment in reference to the observations about the
Air &c.) and consequently the length of the longest and shortest days and
nights, the Climate, parallels &c. what fixt starrs are and what not seen
there: What Constellations 'tis said to be subject to? Whereunto may be
added other Astrological matters, if they be thought worth mentioning.
{187}

2. About the _Air_ may be observ'd, its Temperature, as to the first four
Qualities (commonly so call'd) and the Measures of them: its Weight,
Clearness, Refractive power: its Sublety or Grossness: its abounding with,
or wanting an _Esurine_ Salt: its variations according to the seasons of
the year, and the times of the day; What duration the several kinds of
Weather usually have: What _Meteors_ it is most or least wont to breed; and
in what order they are generated; and how long they usually last:
Especially, what Winds it is subject to; whether any of them be stated and
ordinary, &c. What dise