either by the force of the Waves, or of the Imprisoned Vapors, raised by
the agitation of the Water, and then bursting out with an impetuosity;
witness the noise made by the rupture of the Ice through the whole length
of such Lakes, which _he affirms_ to be not less terrible than if many guns
went off together. Whereby it falls out, that Fishes are seldom found dead
in great Lakes.

6. That neither Oyle, nor a strong Brine of Bay-Salt, is truly {351}
congeal'd into Ice, in those parts, _Viz._ at _Upsall_ in _Sueden_.

7. That the Frost pierces into the Earth, two Cubits or _Swedish_ Ells; and
what moisture is found in it, is white, like Ice: That Waters, if standing,
freeze to a greater depth, even to three such Ells or more; but those that
have a Current, less: That rapid Rivers freeze not at all; nor ever-bubling
Springs; and that these latter seem even to be warmer in Winter, than
Summer.

_So far this Observer_; who likewise offers his Services in giving an
answer to the remaining _Queries_, and in entertaining a commerce in such
other Philosophical matters, as he is conversant in.

_Another_ Paper written by Monsieur _Febre_, chief Secretary to Prince
_Ratzivil_, contains these particulars;

1. That the College of the Learned in _Borussia_, finds it not so easie to
resolve all those _Queries_ sent from _England_ to M. _Heuelius:_ but yet
that they will try what may be done upon it.

2. That as for himself, he can assure from his own Experience concerning
the Effects of Cold; _First_, That in the War against the _Muscovites_ and
_Cosacks_, _A._ 1655. in _January_, in _White Russia_, at the Siege of
_Biskow_, 30. Leagues from _Smolensko_, and three from _Morhilo_, near the
River _Boristhenes_, when they had Quarter in a Village call'd _Bikau_,
they were seized on with such a Frost, that all their Provisions of
_Spanish_ Wines or _Petersimen_, and _Beere_, were in one Night frozen upon
the Sleds, notwithstanding they were cover'd with Straw; in so much, that
when next morning they would have drawn of those Liquors, they found all
dry, and were constrain'd to carry them into a Stove, to thaw them; which
they could not do in two whole days, and were obliged to break the Vessels,
and put pieces of the Icy Wine into Kettles to thaw them over the Fire, for
Drink: That they asked not for a Draught, but a _Morsel_ of Wine or Beer:
That their Horses had no better cheer than themselves, as to matter of
Drink; the Pond of