Quotation from: The Gods of Mars

Written by: Edgar Rice Burroughs

"That is the least of our troubles, Xodar," I replied. "I will
guarantee to scale the wall and take you with me, if you will help
with your knowledge of the customs here to appoint the best time
for the attempt, and guide me to the shaft that lets from the dome
of this abysmal sea to the light of God's pure air above."

"Night time is the best and offers the only slender chance we have,
for then men sleep, and only a dozing watch nods in the tops of
the battleships. No watch is kept upon the cruisers and smaller
craft. The watchers upon the larger vessels see to all about them.
It is night now."