Quotation from: The Chessmen of Mars

Written by: Edgar Rice Burroughs

"And may the spirits of your ancestors surround you," said I-Gos.

After the old man had left him Gahan made his way across the roof
to the high tower, which appeared to have been constructed of
concrete and afterward elaborately carved, its entire surface
being covered with intricate designs cut deep into the stone-like
material of which it was composed. Though wrought ages since, it
was but little weather-worn owing to the aridity of the Martian
atmosphere, the infrequency of rains, and the rarity of dust
storms. To scale it, though, presented difficulties and danger
that might have deterred the bravest of men--that would,
doubtless, have deterred Gahan, had he not felt that the life of
the woman he loved depended upon his accomplishing the hazardous
feat.