inhabitable; but, as
it is, this gas circles round within itself and remains stationary. Hence
creatures that fly high enough above it and such as remain to one side are
safe. I saw another opening like it at Hierapolis in Asia, and tested it
by means of birds; I bent over it myself and myself gazed down upon the
vapor. It is enclosed in a sort of a cistern and a theatre had been built
over it. It destroys all living things save human beings that have been
emasculated. The reason for that I can not comprehend. I relate what I
have seen as I have seen it and what I have heard as I have heard it.

[Sidenote: A.D. 116 (a.u. 869)] Trajan had planned to conduct the
Euphrates through a channel into the Tigris, in order that boats might be
floated down by this route, affording him an opportunity to make a bridge.
But on learning that it had a much higher elevation than the Tigris, he
did not do it, fearing that the water might rush pell-mell down hill and
render the Euphrates unnavigable. So he conveyed the boats across by means
of hauling engines at the point where the space between the rivers is the
least--the whole stream of the Euphrates empties into a swamp and from
there somehow joins the Tigris--then crossed the Tigris and entered
Ctesiphon. Having taken possession of this town he was saluted as
imperator and established his right to the title of Parthicus. Various
honors were voted him by the senate, among others the privilege of
celebrating as many triumphs as he might desire.

After his capture of Ctesiphon he felt a wish to sail down into the Red
Sea. This is a part of the ocean and has been so named [Footnote: [Greek:
erythra] from Erythras, who was said to have been drowned in it (as if in
English we should invent a King Redd).] from some person formerly ruler
there. Mesene, the island in the Tigris of which Athambelus was king, he
acquired without difficulty. [And it remained loyal to Trajan, although
ordered to pay tribute.] But through a storm, and the violence of the
Tigris, and the backward flow from the ocean, he fell into danger. The
inhabitants of the so-called palisade of Spasinus [they were subject to
the dominion of Athambelus] received him kindly.

[Sidenote:--29--] Thence he came to the ocean itself, and when he had
learned its nature and seen a boat sailing to India, he said: "I should
certainly have crossed over to the Indi, if I were still young." He gave
much thought to the Indi, and was curious