NOTE VIII. p. 31.

The notion of the ancients concerning fuch an exceffive degree of heat in the torrid zone, as rendered it uninhabitable, and their perfifting in this error long after they began to have some commercial intercourse with several parts of India lying within the tropicks, must appear fo fingular and abfurd, that it may not be unacceptable to fome, of my readers to produce evidence of their holding this opinion, and to account for the apparent inconfiftence of their theory with their experience. Cicero, who had bestowed attention upon every part of philofophy known to the ancients, feems to have believed that the torrid zone was uninhabitable, and, of confequence, that there could be no intercourfe between the northern and fouthern temperate zones. He introduces Africanus thus addreffing the younger Scipio:

You fee this earth encompassed, and as it were bound in by certain zones, of which two, at the greatest distance from each other, and sustaining the oppofite poles of heaven, are frozen with perpetual cold; the middle one, and the largest of all, is burnt with the heat of the fun; two are habitable, the people in the fouthern one are antipodes to us, with whom we have no connection." Somnium Scipionis, c. 6. Geminus, a Greek philofopher, contemporary with Cicero, delivers the ROBERTSON. Tom. I.

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of

fame doctrine, not in a popular work, but in his Εισαγωγή εις φαινόμενα, a treatife purely fcientinck.,, When we fpeak, fays he,,, the fouthern temperate zone, and its inhabitants, and concerning those who are called antipodes, it must be always understood, that we have no certain knowledge or information concerning the fouthern temperate zone, whether it be inhabited or not. But from the fpherical, figure of the earth, and the course which the fun holds between the tropicks, we conclude that there is another zone, fituated to the fouth, which enjoys the fame degree of temperature with the northern one which we inhabit. " Cap. xiii. p. 31. ap. Petavii Opus de Doctr. Temp. in quo Uranologium five Syftemata var. Auctorum. Amft. 1705. vol. iii. The opinion of Pliny the naturalift, with respect to both these points, was the fame: There are five divifions of the earth, which are called All that portion which lies near to the two oppofite poles is oppreffed with vehement cold, and eternal froft. There, unbleft with the afpect of milder ftars, perpetual darkness reigns, or at the utmost a feeble light reflected from furrounding fnows. The middle of the earth, in which is the orbit of the fun, is fcorched and burnt up with flames and fiery vapour. Between these torrid and frozen diftricts lie two other portions of the earth, which are temperate; but, on account of the burning

zones.

region interpofed, there can be no communication between them. Thus Heaven has deprived us of three parts of the earth." Lib. ii. c. 68. Strabo delivers his opinion to the fame effect, in terms no lefs explicit: The portion of the earth which lies near the equator, in the torrid zóne, is rendered uninhabitable by heat. "Lib. ii. p. 154. To thefe I might add the authority of many other refpectable philofophers and hiftorians of antiquity.

In order to explain the fenfe in which this doctrine was generally received, we may obferve, that Parmenides, as we are informed by Strabo, was the first who divided the earth into five zones, and he extended the limits of the zone which he fuppofed to be uninhabitable on account of heat, beyond the tropicks. Ariftotle, as we learn likewife from Strabo, fixed the boundaries of the different zones in the fame manner as they are defined by modern geographers. But the progrefs of difcovery having gradually demonftrated that feveral regions of the earth which lay within the tropicks were not only habitable, but populous and fertile, this induced later geographers to circumfcribe the limits of the torrid zone. It is not easy to afcertain with precifion the boundaries which they allotted to it. From a paffage in Strabo, who, as far as I know, is the only author of antiquity from whom we receive any hint concerning this fubject, I fhould conjecture, that

those who calculated according to the measurement of the earth by Eratofthenes, fuppofed the torrid zone to comprehend near fixteen degrees, about eight on each fide of the equator; whereas fuch as followed the computation of Pofidonius allotted about twenty-four degrees, or fomewhat more than twelve degrees on each fide of the equator to the torrid zone, Strabo lib. ii. p. 151. According to the former opinion, about two thirds of that portion of the earth which lies between the tropicks was confidered as habitable; according to the latter, about one half of it. With this restriction, the doctrine of the ancients concerning the torrid zone appears lefs abfurd; and we can conceive the reafon of their afferting this zone to be uninhabitable, even after they had opened a communication with feveral places within the tropicks. When men of science spoke of the torrid zone, they confidered it as it was limited by the definition of geographers to fixteen, or at the utmost to twenty-four degrees; and as they knew almost nothing of the countries nearer to the equator, they might still suppose them to be uninhabitable. In loofe and popular discourse, the name of the torrid zone continued to be given to all that portion of the earth which lies within the tropicks. Cicero feems to have been unacquainted with thofe ideas of the later geographers, and adhering to the divifion of Parmenides, defcribes the torrid zone

as the largest of the five. Some of the ancients rejected the notion concerning the intolerable heat of the torrid zone as a popular error. This, we are told by Plutarch, was the fentiment of Pythagoras, and we learn from Strabo, that Eratofthenes and Polybius had adopted the fame opinion, lib. ii. 154. Ptolemy feems to have paid no regard to the ancient doctrine and opinions concerning the torrid zone.

NOTE IX. p. 55.

The court of inquifition, which effectually checks a spirit of liberal inquiry, and of literary improvement, wherever it is established, was firft introduced into Portugal by John III. who began his reign A. D. 1521.

NOTE X. p. 65.

An inftance of this is related by Hackluyt, upon the authority of the Portuguese hiftorian Garcia de Refende. Some English merchants having refolved to open a trade with the coaft of Guinea, John II. of Portugal dispatched ambaffadors to Edward IV., in order to lay before him the right with he had acquired by the Pope's bull to the dominion of that country, and to request of him to prohibit his subjects to profecute their intended voyage. Edward was fo much fatisfied with the exclufive title of the