[Sidenote:  The twilights are shorter, and the nights darker vnder the Equinoctiall then at Paris.] Also this is an other reason, that when the Sunne setteth to them vnder the Equinoctiall, it goeth very deepe and lowe vnder their Horizon, almost euen to their Antipodes, whereby their twilights are very short, and their nights are made very extreeme darke and long, and so the moysture and coldnesse of the long nights wonderfully encreaseth, so that at length the Sunne rising can hardly in many houres consume and driue away the colde humours and moyst vapours of the night past, which is cleane contrary in the Parallel of Paris:  for the Sunne goeth vnder their Horizon but very little, after a sloping sort, whereby their nights, are not very darke, but lightsome, as looking into the North in a cleare night without cloudes it doeth manifestly appeare, their twilights are long:  for the Parallel of Cancer cutteth not the Horizon of Paris at right Angles, but at Angles very vneuen, and vnlike as it doeth the Horizon of the Equinoctiall.  Also the Sommer day at Paris is sixteene houres long, and the night but eight:  where contrarywise vnder the Equinoctiall the day is but twelue houres long, and so long is also the night, in whatsoeuer Parallel the Sunne be:  and therefore looke what oddes and difference of proportion there is betweene the Sunnes abode aboue the Horizon in Paris, and the abode it hath vnder the Equinoctiall, (it being in Cancer) the same proportion would seeme to be betweene the heate of the one place, and heate of the other:  for other things (as the Angle of the whole arke of the Sunnes progresse that day in both places) are equall.

But vnder the Equinoctiall the presence and abode of the Sunne aboue the Horizon is equall to his absence, and abode vnder the Horizon, eche being twelue houres.  And at Paris the continuance and abode of the Sunne is aboue the Horizon sixteene houres long, and but eight houres absence, which proportion is double, from which if the proportion of the equalitie be subtracted to finde the difference, there will remaine still a double proportion, whereby it seemeth to follow, that in Iune the heate of Paris were double to the heate vnder the equinoctiall.  For (as I haue said) the Angles of the Sunne beames are in all points equall, and the cause of difference is, Mora Solis supra Horizontem, the stay of the Sunne in the one Horizon more then in the other. [Sidenote:  In what proportion the Angle of the Sun beames heateth.] Therefore, whosoeuer could finde out in what proportion the Angle of the Sunne beames heateth, and what encrease the Sunnes continuance doeth adde thereunto, it might expresly be set downe, what force of heat and cold is in all regions.