PREFACE

TO THE

CALOR ET FRIGUS.

1

THE following fragment, which was first printed by Stephens from a MS. in Bacon's own hand, then belonging to the Earl of Oxford, and now in the British Museum (Harl. 6855.), is here reprinted from the original. By the general title Sequela Cartarum, and the heading Sectio ordinis, &c., it appears to have been designed for the commencement of a methodical enquiry; but it breaks off at so early a stage that no new light can be gathered from it; and the plan upon which Bacon at this time proposed to proceed in these investigations he afterwards materially altered. For the final shape which his speculations concerning Heat and Cold took, see the second book of the Novum Organum.

J. S.

This heading is carefully and fairly written out in Bacon's Roman hand at the top of every page; not in a single line, as it is here printed, but thus:

Calor et Frigus

Sectio ordinis

Carta Suggestionis.

SEQUELA CARTARUM;

SIVE

INQUISITIO LEGITIMA DE CALORE ET FRIGORE.

Sectio Ordinis.

Carta Suggestionis, sive Memoria Fixa.

THE sun-beams hot to sense.

The moon-beams not hot2, but rather conceived to have a quality of cold, for that the greatest colds are noted to be about the full, and the greatest heats about the change.3 Qu.

The beams of the stars have no sensible heat by themselves; but are conceived to have an augmentative heat of the sunbeams by the instances following.

The same climate arctic and antarctic are observed to differ

in cold, vt. that the antarctic is the more cold, and it is manifest the antarctic hemisphere is thinner planted of

stars.

The heats observed to be greater in July than in June; at which time the sun is nearest the greatest fixed stars,

1 Spelt whott in MS., and so throughout.

2 Compare on this point Vol. I. pp. 239. and 624. Since Mr. Ellis's notes on those passages were in type, a more decisive experiment appears to have been made as to the calorific property of the moon's rays. In Mr. C. Piazzi Smyth's "Notes of Proceedings during the Astronomical Expedition to Teneriffe," date 14 Oct. 1856, I find the following paragraph: "Happier was the enquiry into the radiation of the moon, by means of the Admiralty delicate thermomultiplier, lent by Mr. Gassiot. The position of the moon was by no means favourable, being, on the night of the full, 19 deg. south of the equator; but the air was perfectly calm, and the rare atmosphere so favourable to radiation, that a very sensible amount of heat was found, both on this and the following night. The absolute amount was small, being about one-third of that radiated by a candle at a distance of 15 feet; but the perfect capacity of the instrument to measure smaller quantities still, and the confirmatory result of groups of several hundred observations, leave no doubt of the fact of our having been able to measure here a quantity which is so small as to be altogether inappreciable at lower altitudes."

The last clause is omitted in the Novum Organum.

vt. Cor Leonis, Cauda Leonis, Spica Virginis, Sirius, Canicula.

The conjunction of any two of the three highest planets noted to cause great heats.

Comets conceived by some to be as well causes as effects of heat, much more the stars.

The sun-beams have greater heat when they are more perpendicular than when they are more oblique: as appeareth in difference of regions, and the differences of the times of summer and winter in the same region; and chiefly in the difference of the hours of mid-day, morning, evening in the same day.

The heats more extreme in July and August than in May or June; commonly imputed to the stay and continuance of heat.

The heats more extreme under the tropics than under the line; commonly imputed to the stay and continuance of heat, because the sun there doth as it were double a cape.

The heats more about three or four of clock than at noon; commonly imputed to the stay and continuance of heat.

The sun noted to be hotter when it shineth forth between clouds, than when the sky is open and serene.

The middle region of the air hath manifest effects of cold, notwithstanding locally it be nearer the sun; commonly imputed to antiperistasis, assuming that the beams of the sun are hot either by approach or by reflexion, and that falleth in the middle term between both; or if, as some conceive, it be only by reflexion, then the cold of that region resteth chiefly upon distance. The instances shewing the cold of that region are, the snows which descend, the hails which descend, and the snows and extreme colds which are upon high mountains.

But qu. of such mountains as adjoin to sandy vales, and not to fruitful vales, which minister no vapours; or of mountains above the region of vapours, as is reported of Olympus, where any inscription upon the ashes of the altar remained untouched of wind or dew. And note it is also reported that men carried up sponges with vinegar to thicken their breath, the air growing too fine for respiration, which seemeth not to stand with coldness.

The clouds make a mitigation of the heat of the sun. So

doth the interposition of any body, which we term shades; but yet the nights in summer are many times as hot to the feeling of men's bodies as the days are within doors, where the beams of the sun actually beat not.1

There is no other nature of heat known from the celestial bodies or from the air, but that which cometh by the sun-beams. For in the countries near the pole, we see the extreme colds even in the summer months, as in the voyage of Nova Zembla, where they could not disengage their barque from the ice, no not in July, and met with great mountains of ice some floating some fixed, at that time of the year, being the heart of

summer.

The caves under the earth noted to be warmer in winter than in summer, and so the waters that spring from within the earth.

Great quantity of sulphur, and sometimes naturally burning after the manner of Etna, in Iceland; the like written of Gronland, and divers other the cold countries.2

The trees in the cold countries are such as are fuller of rosin, pitch, tar, which are matters apt for fire, and the woods themselves more combustible than those in much hotter countries; as, for example, fir, pineapple, juniper: Qu. whether their trees of the same kind that ours are, as oak and ash, bear not, in the more cold countries, a wood more brittle and ready to take fire than the same kinds with us?

The sun-beams heat manifestly by reflexion, as in countries pent in with hills, upon walls or buildings, upon pavements, upon gravel more than earth, upon arable more than grass, upon rivers if they be not very open, &c.

3

The uniting or collection of the sun-beams multiplieth heat, as in burning-glasses, which are made thinner in the middle than on the sides (as I take it contrary to spectacles); and the operation of them is, as I remember, first to place them between the sun and the body to be fired, and then to draw them upward towards the sun, which it is true maketh the angle of

The following note is inserted here in the margin :— No doubt but infinite power of the heat of the sun in cold countries, though it be not to the analogy of men, and fruits, &c.

2 Opposite to this and to the nine preceding paragraphs, is written in the margin Aug.

So MS. Compare Vol. I. p. 241. (where the error is avoided, though not corrected) and p. 253, note 1.