studies which carried the observer all round the world. That was in
1845--46, during the United States Exploring Expedition that visited
the then little known Japan. The chaplain of the fleet, the Rev. Mr
Jones, went out prepared to study the mysterious light in all its
phases. He saw it from many latitudes on both sides of the equator,
and the imagination cannot but follow him with keen interest in his
world-circling tour, keeping his eyes every night fixed upon the
phantasm overhead, whose position shifted with that of the hidden sun.
He demonstrated that the flow extends at times completely across the
celestial dome, although it is relatively faint directly behind the
earth. On his return the government published a large volume of his
observations, in which he undertook to show that the phenomenon was
due to the reflection of sunlight from a ring of meteoric bodies
encircling the earth. But, after all, this elaborate investigation
settled nothing.

Prof. E. E. Barnard has more recently devoted much attention to the
Zodiacal Light, as well as to a strange attendant phenomenon called
the ``Gegenschein,'' or Counterglow, because it always appears at that
point in the sky which is exactly opposite the sun. The Gegenschein is
an extremely elusive phenomenon, suitable only for eyes that have been
specially trained to see it. Professor Newcomb has cautiously remarked
that

it is said that in that point of the heavens directly opposite the
sun there is an elliptical patch of light... This phenomenon is so
difficult to account for that its existence is sometimes doubted;
yet the testimony in its favor is difficult to set aside.

It certainly cannot be set aside at all since the observations of