fhelter them every Winter in a common Greenhoufe, fo that no Froft may invade them.

After this, as we come nearer to the Tropicks, or the Line, we must be diligent to give the Plants the feveral Degrees of Watering natural to the respective Climates; and for that end we fhould learn when the Seasons are that the Rains fall in Countries of different Latitudes. Nor fhould we too inadvertently attempt to harden Plants, but rather feek to increase their Strength, by making them grow and increase in their Bodies; for in the common Way of making them hardy, though they yet live with us, they lofe their natural Intent of bearing Fruit, and fo become useless.

In the Culture of Plants therefore, it is not enough only to give them fuch a Share of Warmth or Shelter, as will barely keep them alive; but we must give them fuch Heat at proper Seasons, as may equal, if poffible, that of their native Country, which in a particular manner should be regarded in the Culture of fuch Plants as grow between the Tropicks; but that has remain'd an Uncertainty, till Mr. Telende luckily discover'd the Degree of warm Air in Nevis and St. Chriftopher's, where the PineApples chiefly delight themselves; and as they fucceed under the Influence of the Heat he gives them, fo we may be fure, every other Plant growing in the fame Degree of Latitude may be made to profper with us, whether they come from the North or South Side of the Line.

It is neceffary likewife to obferve the Course of the Sun, in the Culture of Plants which come from any of those Latitudes mark'd in the Thermometer, and apply to them the stronge

Heats

Heats of their refpective Countries, at the Time when the Sun is nearest those Places which they were brought from; and when we receive Plants from Countries where the Sun paffes over twice in a Year, our artificial Heats fhould at fuch Times be chiefly fupported.

Thus, Sir, I have mention'd what I think will be neceflary for your Ufe at this Time, with regard to the Thermometer; but when Í know the State of your Climate, can fay more: In the mean while, though I am unknown to your Perfon, I am no Stranger to your Merits, and conclude,

Your most humble Servant,

to command,

R. BRADLEY.

Mr. Clark of Oporto's Answer to the foregoing Letter.

I

To Mr. Bradley, F. R. S. London.

SIR,

Oporto, April 16, 1723.

Am extreamly oblig'd to you for your Fa vour of the 28th of January, and the Advice you give me concerning the Culture of the Ananas I have had much Trouble to preferve the two Plants my Father fent me, through the little Care Mafters of Ships generally take in

bringing

bringing Plants; and befides, I have not had the Opportunity to mind their Propagation fo well as to expect Fruit from them this Seafon, but am fully bent upon all Diligence for to have it

the next.

The Ananas is a Plant very common in the Portugueze Colonies in Brazil, fo that few Seafaring Perfons and Factors who have been there, are unacquainted with it.

Doubtlefs, the Thermometer you have contriv'd, to fhew the proper Degrees of Heat natural to each Plant, will render their Culture prodigiously eafy; I impatiently expect that which you have been pleas'd to finish me, for which I give you my hearty Thanks.

We are fituated here within a League of the Sea, in a hilly, rocky Country; few Grounds are improv'd, but what are humid, or else have little Springs of Water near them, to moisten in Summer Time. In our Wine Country, which is about fixty Miles diftant, Eastward, the Heat and Cold is more exceffive than with us, by reason the Mountains are much higher and steeper. The Summer Western Sea-Breezes do not reach that Country; and the Reverberation of the Sun from thofe rocky Hills heat the Air to fuch a Degree, that the Night in the Summer Season is as hot as the Day.

We have our Spring fooner about a Month than in your Climate, and the fame Continuance of good Weather longer in Autumn. The Winter Air is very fharp and piercing to Plants, though we feel little or no cold Weather; but I fuppofe the Reason is, that our Air is more fubtle, and not fo condens'd as yours is. I have known in Winter a continual Rain for fix Weeks,

Weeks, but fome Years we escape without any. Our worft Months are from the middle of December to the middle of February; for in the latter End we reckon Spring begins.

I obferv'd, in fome of your Writings, the Experiment of cutting or laying the Branches of a Tree in the Ground, and the next Seafon raifing the Roots into the Air, which will do the Office of the former Branches. It is the Practice here to do fo in the Increase of the Figtree, because they find it very tedious before it will bear from Suckers. Their Method is laying the top Boughs of any Branch into the Ground, and in the new Seafon fawing off the Branch, and ftaking it as upright as poffible; which top Stump in the Air will fhoot vigoroufly, and quickly give Fruit: I am told, that the China Orange may be us'd fo; and then, they fay, the Fruit of the new made Tree is without Kernels.

A Fryar has promis'd to graff me this Seafon the Carnation upon Fennel; he fays, the Flower will be entirely green, as well as the Plant; and, he affures me, the Colour will keep two or three Years the fame, and after that, changes to the Colours common to that Flower. He adds, that in this Country the beft Stock for graffing Stone Fruit upon, is the Peach, for its Flavour is communicated into the Fruit of the Graff; as likewife, if you graff a Peach upon a Mulberry, the Fruit will have the purple Dye to the Stone, and the pleasant acid Flavour. If I can make any Obfervations here worth your Notice, I fhall communicate them to you with Pleafure: The Natives are the leaft curious in Gardening of any Nation in Europe; any Thing uncommon

Concerning Quickfilver found in England, and of the Barometer and Ther mometer, in a Letter to W. Waller, Efq; particularly, how far thofe Inftruments are neceffary in the Culture of Exotick

Plants.

SIR,

I

Had the Favour of your Letter concerning Minerals and fubterraneous Riches, which I am very senfible abound in our British Soil,

and fuch as are already difcover'd and understood, bring great Profit to the Nation; but I am affur'd, there are many others that are daily before us, which are at present usclefs for want of the right Knowledge of