Callicratidas, hearing that the relief squadron had already reached
Samos, left fifty ships, under command of Eteonicus, in the harbour of
Mitylene, and setting sail with the other one hundred and twenty, hove
to for the evening meal off Cape Malea in Lesbos, opposite Mitylene.
It so happened that the Athenians on this day were supping on the
islands of Arginusae, which lie opposite Lesbos. In the night the
Spartan not only saw their watch-fires, but received positive
information that "these were the Athenians;" and about midnight he got
under weigh, intending to fall upon them suddenly. But a violent
downpour of rain with thunder and lightning prevented him putting out
to sea. By daybreak it had cleared, and he sailed towards Arginusae.
On their side, the Athenian squadron stood out to meet him, with their
left wing facing towards the open sea, and drawn up in the following
order:--Aristocrates, in command of the left wing, with fifteen ships,
led the van; next came Diomedon with fifteen others, and immediately
in rear of Aristocrates and Diomedon respectively, as their supports,
came Pericles and Erasinides. Parallel with Diomedon were the Samians,
with their ten ships drawn up in single line, under the command of a
Samian officer named Hippeus. Next to these came the ten vessels of
the taxiarchs, also in single line, and supporting them, the three
ships of the navarchs, with any other allied vessels in the squadron.
The right wing was entrusted to Protomachus with fifteen ships, and
next to him (on the extreme right) was Thrasylus with another division
of fifteen. Protomachus was supported by Lysias with an equal number
of ships, and Thrasylus by Aristogenes. The object of this formation
was to prevent the enemy from manouvring so as to break their line by
striking them amidships,[11] since they were inferior in sailing
power.

[11] Lit. "by the diekplous." Cf. Thuc. i. 49, and Arnold's note, who