no less than twenty-five minutes (more than six times
Airy's estimate), while the great plumes spread their radiance to three
or four degrees from the dark lunar edge. So dazzling was the light that
many well-instructed persons denied the totality of the eclipse. Nor was
the error without precedent, although the appearances attending
respectively a total and an annular eclipse are in reality wholly
dissimilar. In the latter case, the surviving ring of sunlight becomes
so much enlarged by irradiation, that the interposed dark lunar body is
reduced to comparative insignificance, or even invisibility. Maclaurin
tells us[159] that during an eclipse of this character which he observed
at Edinburgh in 1737, "gentlemen by no means shortsighted declared
themselves unable to discern the moon upon the sun without the aid of a
smoked glass;" and Baily (who, however, _was_ shortsighted) could
distinguish, in 1836, with the naked eye, no trace of "the globe of
purple velvet" which the telescope revealed as projected upon the face
of the sun.[160] Moreover, the diminution of light is described by him
as "little more than might be caused by a temporary cloud passing over
the sun"; the birds continued in full song, and "one cock in particular
was crowing with all his might while the annulus was forming."

Very different were the effects of the eclipse of 1842, as to which some
interesting particulars were collected by Arago.[161] Beasts of burthen,
he tells us, paused in their labour, and could by no amount of
punishment be induced to move until the sun reappeared. Birds and beasts
abandoned their food; linnets were found dead in their cages; even ants
suspended their toil. Diligence-horses, on the other hand, seemed as
insensible to the phenomenon as locomotives. The convolvulus and some
other plants closed their leaves, but those of the mimosa remained open.
The little light that remained was of a livid hue. One observer
described the general coloration as resembling the lees of wine, but
human faces showed pale olive or greenish. We may, then, rest assured
that none of the remarkable obscurations recorded in history were due to
eclipses of the annular kind.

The existence of the corona is no modern discovery. Indeed, it is too
conspicuous an apparition to escape notice from the least attentive or
least practised observer of a total eclipse. Nevertheless, explicit
references to it are rare in early times. Plutarch, however, speaks o