te, that 'twas not without some
Wonder, that I made the Observation. Besides, though we in _English_ are
wont to say, a thing is Red hot, as an Expression of its being
Superlatively _Ignitum_, (if I may so Speak for want of a proper _English_
word) yet in the Forges of Smiths, and the Furnaces of other Artificers, by
that which they call a White heat, they mean a further Degree of
_Ignition_, than by that which both they and we call a Red heat.

5. Secondly, I consider, that common Experience informs us, that as much
Light Over-powers the Eye, so when the Ground is covered with Snow, (a Body
extremely White) those that have Weak Eyes are wont to complain of too much
Light: And even those that have not, are generally Sensible of an
Extraordinary measure of Light in the Air; and if they are fain to Look
very long upon the Snow, find their Sight Offended by it. On which occasion
we may call to mind what _Xenophon_ relates, that his _Cyrus_ marching his
Army for divers days through Mountains covered with Snow, the Dazling
splendor of its Whiteness prejudic'd the Sight of very many of his
Souldiers, and Blinded some of them; and other Stories of that Nature be
met with in Writers of good Note. And the like has been affirm'd to me by
credible Persons of my own Acquaintance, and especially by one who though
Skill'd in Physick and not Ancient confess'd to me when I purposely ask'd
him, that not only during his stay in _Muscovy_, he found his Eyes much
Impair'd, by being reduc'd frequently to Travel in the Snow, but that the
Weakness of his Eyes did not Leave him when he left that Country, but has
follow'd him into these Parts, and yet continues to Trouble him. And to
this doth agree what I as well as others have observ'd, namely, that when I
Travell'd by Night, when the Ground was all cover'd with Snow, though the
Night otherwise would not have been Lightsome, yet I could very well see to
Choose my way. But much more Remarkable to my present purpose is that,
which I have met with in _Olaus Magnus_,[8] concerning the way of
Travelling in Winter in the _Northern_ Regions, where the Days of that
Season are so very Short; for after other things not needfull to be here
Transcribed: _Iter_, says he, _Diurnum duo scilicet montana milliaria (quae
12 Italica sunt) consiciunt. Nocte vero sub splendissima luna, duplatum
iter consumunt aut triplatum. Neque id incommode fit, cum nivium
reverberatione lunaris splendoris sublimes & declives cam