hquake in the younger dayes of the world. But that
which does most incline me to this belief, is, first, the generality and
diversity of the Magnitude of these pits all over the body of the Moon.
Next, the two experimental wayes, by which I have made a representation of
them.

The first was with a very soft and well temper'd mixture of Tobacco-pipe
clay and Water, into which, if I let fall any heavy body, as a Bullet, it
would throw up the mixture round the place, which for a while would make a
representation, not unlike these of the Moon; but considering the state and
condition of the Moon, there seems not any probability to imagine, that it
should proceed from any cause _analogus_ to this; for it would be difficult
to imagine whence those bodies should come; and next, how the substance of
the Moon should be so soft; but if a Bubble be blown under the surface of
it, and suffer'd to rise, and break; or if a Bullet, or other body, sunk in
it, be pull'd out from it, these departing bodies leave an impression on
the surface of the mixture, exactly like these of the Moon, save that these
also quickly subside and vanish. But the second, and most notable,
representation was, what I observ'd in a pot of boyling Alabaster, for
there that powder being by the eruption of vapours reduc'd to a kind of
fluid consistence, if, whil'st it boyls, it be gently remov'd besides the
fire, the Alabaster presently ceasing to boyl, the whole surface,
especially that where some of the last Bubbles have risen, will appear all
over covered with small pits, exactly shap'd like these of the Moon, and by
holding a lighted Candle in a large dark Room, in divers positions to this
surface, you may exactly represent all the _Phaenomena_ of these pits in
the Moon, according as they are more or less inlightned by the Sun.

And that there may have been in the Moon some such motion as this, which
may have made these pits, will seem the more probable, if we suppose it
like our Earth, for the Earthquakes here with us seem to proceed from some
such cause, as the boyling of the pot of Alabaster, there seeming to be
generated in the Earth from some subterraneous fires, or heat, great
quantities of vapours, that is, of expanded aerial substances, which not
presently finding a passage through the ambient parts of the Earth, do, as
they are increased by the supplying and generating principles, and thereby
(having not sufficient room to expand themselves) extreamly c