ienthal observer to rise to the prodigious height of nearly
twenty-seven miles, or just five times the elevation of Mount Everest!
Yet the phenomenon persists, whatever may be thought of the explanation.
Moreover, the speck of light beyond, interpreted as the visible sign of
a detached peak rising high enough above the encircling shadow to catch
the first and last rays of the sun, was frequently discerned by Baron
Van Ertborn in 1876;[859] while an object near the northern horn of the
crescent, strongly resembling a lunar ring-mountain, was delineated both
by De Vico in 1841 and by Denning forty years later.

We are almost equally sure that Venus, as that the earth is encompassed
with an atmosphere. Yet, notwithstanding luminous appearances plainly
due to refraction during the transits both of 1761 and 1769, Schroeter,
in 1792, took the initiative in coming to a definite conclusion on the
subject.[860] It was founded, first, on the rapid diminution of
brilliancy towards the terminator, attributed to atmospheric absorption;
next, on the extension beyond a semicircle of the horns of the crescent;
lastly, on the presence of a bluish gleam illuminating the early hours
of the Cytherean night with what was taken to be genuine twilight. Even
Herschel admitted that sunlight, by the same effect through which the
heavenly bodies show _visibly above_ our horizons while still
_geometrically below_ them, appeared to be bent round the shoulder of
the globe of Venus. Ample confirmation of the fact has since been
afforded. At Dorpat in May, 1849, the planet being within 3 deg. 26' of
inferior conjunction, Maedler found the arms of waning light upon the
disc to embrace no less than 240 deg. of its extent;[861] and in December,
1842, Mr. Guthrie, of Bervie, N.B., actually observed, under similar
conditions, the whole circumference to be lit up with a faint nebulous
glow.[862] The same curious phenomenon was intermittently seen by Mr.
Leeson Prince at Uckfield in September, 1861;[863] but with more
satisfactory distinctness by Mr. C. S. Lyman of Yale College,[864]
before and after the conjunction of December 11, 1866, and during nearly
five hours previous to the transit of 1874, when the yellowish ring of
refracted light showed at one point an approach to interruption,
possibly through the intervention of a bank of clouds. Again, on
December 2, 1898, Venus being 1 deg. 45' from the sun's centre, Mr. H. N.
Russell, of the Halsted Observator