r at Sohag,
a bright comet appeared near the outer limit of the corona (see Plate
I., p. 96). The comet in question had not been seen before the eclipse,
and was never seen afterwards. This is the third occasion on which
attention has been drawn to a comet _merely_ by a total eclipse. The
first is mentioned by Seneca; and the second by Philostorgius, in an
account of an eclipse observed at Constantinople in A.D. 418. A fourth
case of the kind occurred in 1893, when faint evidences of one of these
filmy objects were found on photographs of the corona taken by the
American astronomer, Professor Schaeberle, during the total eclipse of
April 16 of that year.

The eclipse of May 6, 1883, had a totality of over five minutes, but
the central track unfortunately passed across the Pacific Ocean, and the
sole point of land available for observing it from was one of the
Marquesas Group, Caroline Island, a coral atoll seven and a half miles
long by one and a half broad. Nevertheless astronomers did not hesitate
to take up their posts upon that little spot, and were rewarded with
good weather.

The next eclipse of importance was that of April 16, 1893. It stretched
from Chili across South America and the Atlantic Ocean to the West Coast
of Africa, and, as the weather was fine, many good results were
obtained. Photographs were taken at both ends of the track, and these
showed that the appearance of the corona remained unchanged during the
interval of time occupied by the passage of the shadow across the earth.
It was on the occasion of this eclipse that Professor Schaeberle found
upon his photographs those traces of the presence of a comet, to which
allusion has already been made.

Extensive preparations were made to observe the eclipse of August 9,
1896. Totality lasted from two to three minutes, and the track stretched
from Norway to Japan. Bad weather disappointed the observers, with the
exception of those taken to Nova Zembla by Sir George Baden Powell in
his yacht _Otaria_.

The eclipse of January 22, 1898, across India _via_ Bombay and Benares,
was favoured with good weather, and is notable for a photograph obtained
by Mrs. E.W. Maunder, which showed a ray of the corona extending to a
most unusual distance.

[Illustration: PLATE I. THE TOTAL ECLIPSE OF THE SUN OF MAY 17TH, 1882

A comet is here shown in the immediate neighbourhood of the corona.

Drawn by Mr. W.H. Wesley from the photographs.

(Page 95)]

Of very gr