16. Countries where the attendant winds are warm are hotter, and countries where these winds are cool are colder, than in proportion to their climate.

A Map or Table of Human Requirements with reference to the Winds; or Desiderata with their Approximations.

Desideratum. 1. A better method of ordering and disposing the sails of ships, so as to make more way with less wind; a thing very useful in shortening sea voyages, and saving expense.

Approximation. No approximation has been hitherto invented which in practice should exactly correspond to this requirement. But for this consult the major observations on the 26th article.

Desideratum. 2. A method of constructing windmills with sails, so as to grind more with less wind; a thing likewise useful and lucrative.

Approximation. Consult on this point our experiments in reply to the 27th article, where the thing appears to be almost done.

Desideratum. 3. A method of foreknowing the risings, fallings, and times of winds; a thing useful in navigation and agriculture, but especially so in selecting the times for naval engagements.

Approximation. Many things have been remarked in the inquiry which bear upon this subject, but especially the reply to the 32nd article. Now however that the cause of the winds is explained, the more diligent observations of posterity (if it shall care at all about these things) will discover more certain prognostics.

Desideratum. 4. A method of prognosticating and forming an opinion upon other things by means of the

winds; for instance, whether in any part of the sea there are continents or islands, or whether the sea is open; a thing of use in new and unknown navigations.

Approximation. The observation about the periodical winds, which Columbus appears to have used, is an approximation to this.

Desideratum. 5. A method likewise of foretelling, every year, whether corn and fruit will be abundant or scarce; a thing useful and lucrative in speculative sales and purchases; of which an instance is related in the case of Thales when he bought up the olives.1

Approximation. Some observations under the 29th article of inquiry, on malignant or tearing winds, and the times when they are prejudicial, bear upon this point.

Desideratum. 6. A method likewise of foretelling the diseases and epidemics for every year; a thing useful to the reputation of physicians, if such things could be predicted; as also for the causes and cures of diseases, with some other matters of business.

Approximation. Some observations on the 30th article of inquiry have likewise reference to this question. Admonition. For predictions from the winds concerning crops, fruits, and diseases, consult the Histories of Agriculture and Medicines.

Desideratum. 7. A method of raising and allaying winds.

Approximation. There are some superstitious and magical ceremonies connected with this subject, which do not appear worthy to be received into a serious and exact natural history. Nor does any approximation at present occur to me. It will however be of service thereto, to inspect and inquire thoroughly into 1 Diog. Laert. i. 26.

the nature of the air; to see if there be anything which, on being communicated in a small quantity to the air, can excite and multiply the motion of dilatation or contraction in the body of the air. For if this could be done, the raising and calming of the winds would naturally follow; like Pliny's experiment, if it be true, of throwing vinegar against the whirlwind.1 Another method might be, by letting out subterranean winds wherever a great quantity was collected, as is told of the well in Dalmatia. But it is difficult to discover these places of confine

ment.

Desideratum. 8. Methods of performing many amusing and wonderful experiments by the motion of the winds.

Approximation. Such questions I have no time to consider. The approximation is the common games which depend on the wind; and, no question, many pleasant things of this kind, both with regard to sound and motion, may be invented.

1 Pliny ii. 49.

INTRODUCTIONS TO THE TITLES DESIGNED

FOR THE NEXT FIVE MONTHS.

FOR THE INTRODUCTION

TO

THE HISTORY OF DENSE AND RARE,

SEE THE HISTORY.

THE HISTORY OF HEAVY AND LIGHT.

INTRODUCTION.

THE motion of heavy and light was distinguished by the ancients under the name of natural motion. For they saw no external efficient, and no apparent resistance. Moreover this motion seemed to gain rapidity by its progress. To their contemplation or rather discourse on this subject they added by way of seasoning the mathematical fancy that heavy bodies would adhere to the centre of the earth (even if a hole were made through it), together with the scholastic fiction of the motion of bodies to their own places. And believing that by these positions they had settled the question, they made no further inquiry, except that there was one of them who inquired somewhat more diligently concerning the centre of gravity in different figures, and touching the things which float on water. has one of the moderns contributed anything of consequence; having only added a few mechanical inventions, and even those distorted by his demonstrations. But to speak direct, it is quite certain that a body is affected only by a body; and that there is no local motion which is not excited either by the parts of the body moved, or by the adjacent bodies, or by those contiguous or proximate to it, or at least by those

Nor