The successions of the winds.

Enquire whether there be any rule, or certain observation, as to the order in which the winds succeed one another; and whether it be conformable to the sun's motion, or otherwise; and however it be, to discover the fact.

Enquire concerning the succession and interchance of winds and rain: since it is usual for rain to allay the winds; and for the winds to keep up and dissipate rain.

Observe whether the succession of the winds is renewed after a certain period of years; and, if so, to find what that period is.

From the order of succession, let the enquiry glide on to the motions of the winds. The motions of the winds branch themselves into seven distinct enquiries; three whereof are contained in the preceding articles; and four remain hitherto untouched: for we have already mentioned, 1. That motion of them, which regards the points of the compass they blow from. motion in the three lines of direction, upwards, downwards, and sidewise. 3. Their accidental motion by compression; so that there remains, 4. Their progressive motion. 5. Their undulatory motion. 6. Their impinging motion. And, 7. Their motion in organs, and machines of human invention.

2. Their

Different motions of the winds.

As progression always begins from a certain point; let a very careful enquiry be made into the place of the primary rise, or, as it were, first fountain of the winds: for winds resemble fame; and though they tumultuate and bluster every where, yet hide their heads among the clouds. Again, enquire into their progress itself: for example, if a strong north wind blew, upon a certain day and hour, at York; suppose it should, two days afterwards be found to blow at London, &c.

The enquiry into the undulation of the winds must not be omitted. We call that motion the undulation of the winds, wherein a wind, for a small space, increases and slackens, or swells and falls again, like the waves of the sea; the reci✩ procation whereof is known from the sound they make in buildings. And the differences of this undulation, or rising and falling, betwixt the air and water, must be the more carefully observed; because the air and winds have not that great mo❤ tion of gravity, which is the chief cause of the undulation in waters.

Let the enquiry be carefully pursued, with regard to the impinging, or meeting of strong winds together; and blowing at the same time: as first, whether many original winds may blow, and dash

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against one another at once; and, if this happen, what reciprocation it causes in the motion: and again, what condensations and alterations it produces in the body of the air.

Enquire whether some winds do not blow at the same time above, that others blow below : for clouds have been sometimes observed to move in a contrary direction to that of the weathercock; and sometimes to be driven briskly, whilst there was a perfect calm near the surface of the earth.

Let a very exact, careful, and particular description be made of the motion of the winds in the sailing of ships.

Describe the motion of the winds in the sails of wind-mills, the flight of hawks, and other birds; and even in the common phænomena and diversions; as the hoisting of flags and streamers; the flying of paper-kites; fighting of battles by the wind, &c. And now, from the motions, let the enquiry pass on to the force and powers. of the winds.

The powers of the Winds.

have upon

Enquire what effects the winds may the tides and currents; as to keeping them out, driving them in, and causing them to overflow.

Enquire their effect upon vegetables and in

sects; as to their bringing in of locusts, cankerworms, mill-dews, blights, blasts, &c.*

Enquire their effects, as to purging and infect→ ing the air; the producing of pestilences, diseases, and disorders in animals.

Enquire into their manner of conveying those called spiritual species; as sounds, emissions, light,+ &c.

From these powers of the winds, let the enquiry descend to the prognostics of winds; not only for the use of predictions, but on account of their leading up to causes: for prognostics either discover the preparation of things, before they come into action; or their beginnings, before they become manifest to the senses.

Presages or prognostics of Winds.

Let great diligence be used to collect all the kinds of prognostications of winds, except those of an astrological nature; with regard to which we have above laid down our directions: otherwise they may be derived from meteors, waters, the instinct of animals, and many other things.

Lastly, let the whole enquiry be closed by

* Viz. the scattering abroad, and sowing the seeds of vegetables; in different places, &c.

+ See Dr. Derham's paper upon the Motion of Sounds, in the Philosophical Transactions.

searching into methods of imitating the winds, for natural as well as artificial purposes.

Imitations of Winds.

Enquire into the imitations of winds in natural subjects; such are the flatulencies in animal bodies; and the puffings, or displosions of subjects in chemical distillations.

To conclude; let enquiry be made into factitious and artificial winds, gales, and fannings; as by bellows, refrigeratories, or cool-rooms, &c.

Such are the heads requisite to a particular history of the winds; but we expect not that our present stock of experience should be able to answer them all. However, as in trials at law, a good lawyer knows how to put such questions as the case requires; but knows not what the witnesses will answer: so we can proceed no otherwise in the grand cause betwixt nature and mankind; and must leave posterity to see the issue.*

*These articles are not fully spoke to in the following enquiry; and indeed the whole, however great in itself, should be esteemed as little more than the out-lines of a natural history of the wind; that wants to be filled up by fu ture labour, experiments, and observations.