Also our Aucthour of the Sphere, Johannes de Sacro Bosco, in the Chapter of the Zodiacke, deriueth the Etymologie of Zodiacus, of the Greeke word Zoe, which in Latine signifieth Vita, life; for out of Aristotle hee alleadgeth, that Secundum accessum et recessum solis in Zodiaco, fiunt generationes et corruptiones in rebus inferioribus: according to the Sunnes going to and fro in the Zodiake, the inferiour bodies take their causes of generation and corruption. [Sidenote: Vnder the Equinoctiall is greatest generation.] Then it followeth, that where there is most going to and fro, there is most generation and corruption: which must needes be betweene the two Tropikes; for there the Sunne goeth to and fro most, and no where else but there. Therefore betweene the two Tropikes, that is, in the middle Zone, is greatest increase, multiplication, generation, and corruption of things, which also wee finde by experience; for there is Sommer twice in the yeere, and twice Winter, so that they haue two Haruests in the yeere, and continuall Spring. Seeing then the middle Zone falleth out so temperate, it resteth to declare where the hottest part of the world should bee, for we finde some places more hote then others. To answere this doubt, reason perswadeth, the hotest place in[61] the world to bee vnder and about the two Tropikes; for there more then in any other place doe both the [Sidenote: Greatest heate vnder the Tropicks.] causes of heate concurre, that is, the perpendicular falling of the Sunne beames, at right angles, and a greater continuance of the Sunne aboue the Horizon, the Pole there being eleuated three or foure and twentie degrees. And as before I concluded, that though the Sunne were perpendicular to them vnder the Equinoctiall, yet because the same continued but a small time (their dayes being short, and their nights long) and the speedie departure of the Sunne from their Zenith, because of the suddeine crossing of the Zodiake with the Equinoctiall, and that by such continuall course and recourse of hote and colde, the temperature grew moderate, and very well able to bee endured: so nowe to them vnder the two Tropikes, the Sunne hauing once by his proper motion declined twentie degrees from the Equinoctial, beginneth to drawe neere their Zenith, which may bee (as before) about the eleuenth day of May, and then beginneth to sende his beames almost at right Angles, about which time the Sunne entreth into the first degree of Gemini, and with this almost right Angle the Sunne beames will continue vntill it bee past Cancer, that is, the space of two moneths euery day at noone, almost perpendicular ouer their heades, being then the time of Solstitium Aestiuale: which so long continuance of the Sunne about their Zenith may cause an extreeme heate (if any be in the world) but of necessitie farre more heate then can bee vnder the Equinoctiall, where the Sunne hath no such long abode in the Zenith, but passeth away there hence very quickly.