*
*Havelius writes that he has several times found, in skies perfectly
clear, when even stars of the sixth and seventh magnitude were
conspicuous, that, at the same altitude of the moon, at the same
elongation from the earth, and with one and the same excellent
telescope, the moon and its maculae did not appear equally lucid at
all times. From the circumstances of the observation, it is evident
that the cause of this phenomenon is not either in our air, in the
tube, in the moon, or in the eye of the spectator, but must be
looked for in something (an atmosphere?) existing about the moon.
Cassini frequently observed Saturn, Jupiter, and the fixed stars,
when approaching the moon to occultation, to have their circular
figure changed into an oval one; and, in other occultations, he
found no alteration of figure at all. Hence it might be supposed, that
at some times and not at others, there is a dense matter
encompassing the moon wherein the rays of the stars are refracted.
Upon the resistance or, more properly, upon the support of an
atmosphere, existing in the state of density imagined, I had, of
course, entirely depended for the safety of my ultimate descent.
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