"Yet greater was my astonishment when, on the 19th of January, I saw the
canal Jamuna, which was then in the center of the disk, formed very
rigidly of two parallel straight lines, crossing the space which
separates the Niliac Lake from the Gulf of Aurora. At first sight I
believed it was an illusion, caused by fatigue of the eye and some new
kind of strabismus, but I had to yield to the evidence. After the 19th
of January I simply passed from wonder to wonder; successively the
Orontes, the Euphrates, the Phison, the Ganges, and the larger part of
the other canals, displayed themselves very clearly and indisputably
duplicated. There were not less than twenty examples of duplication, of
which seventeen were observed in the space of a month, from the 19th of
January to the 19th of February.

"In certain cases it was possible to observe precursory symptoms which
are not lacking in interest. Thus, on the 13th of January, a light,
ill-defined shade extended alongside the Ganges; on the 18th and the
19th one could only distinguish a series of white spots; on the 20th the
shadow was still indecisive, but on the 21st the duplication was
perfectly clear, such as I observed it until the 23d of February. The
duplication of the Euphrates, of the canal of the Titans, and of the
Pyriphlegethon also began in an uncertain and nebulous form.

"These duplications are not an optical effect depending on increase of
visual power, as happens in the observation of double stars, and it is
not the canal itself splitting in two longitudinally. Here is what is
seen: To the right or left of a pre-existing line, without any change in
the course and position of that line, one sees another line produce
itself, equal and parallel to the first, at a distance generally varying
from six to twelve degrees--i.e., from 350 to 700 kilometres (217 to 434