ore
for the burning of _White_ Bodies, than for the burning of _Black_ ones:
and so observing the immediate proportions between these two, for burning
bodies of _other_ Colors. Whence (he tells us) he hath drawn some
consequences, touching the distance, at which we may hope, to burn Bodies
here, by the means of _great Glasses_ and great _Looking-glasses_. So that
(_saith he_) we must yet be seven times neerer the _Sun_, than we are, to
be in danger of being burned by it. Where he mentions, that having given
_Instructions_ to certain persons, gon to travel in _Hot Countries_, he
hath among other particulars recommended to them, to try by means of great
_Burning-glasses_, with how much less _Aperture_ they will burn _there_,
than _here_, to know from thence, whether there by more Light _there_ than
_here_, and how much; since this perhaps may be the only means of trying
it, supposing, the same matters be used: although the difference of the Air
already heated, both in _hot Countries_, and in the _Planets_, that are
neerer than we, may alter, if not the quantity of Light, at least that of
the Heat, found there.

* * * * *

_A further Account, touching Signor _Campani_'s Book and Performances about
_Optick-glasses_._

In the above-mentioned _French_ Tract there is also conteined M. _Auzout's_
Opinion of what he had found New in the _Treatise_ of Signor _Campani_,
which was spoken of in the first _Papers_ of these _Transactions_,
concerning both the Effect of the _Telescopes_, contrived after a peculiar
way by the said _Campani_ at _Rome_, and {71} his New Observations of
_Saturn_ and _Jupiter_, made by means thereof.

First therefore, after that M _Auzout_ had raised some scruple against the
Contrivance of Signor _Campani_ for making _Great Optick-Glasses_ without
_Moulds_, by the means of a _Turn-lath_, he examines the _Observations_,
made with such _Glasses_: Where, having commended _Campani_'s sincerity in
relating what he thought to have seen in _Saturn_, without accomodating it
to M. _Hugens_'s _Hypothesis_, he affirms, that supposing, there be a
_Ring_ about _Saturn_, Signor _Campani_ could not see in all those
different times, that he observed it, _the same Appearances_, which he
notes to have _actually_ seen. For, having seen it sometimes in _Trine
Aspect_ with the _Sun_, and _Oriental_; sometimes, in the same _Aspect_,
but _Occidental_; sometimes in _Sextil Aspect_, and _Occidental