Westy Martin in the Rockies by Percy Keese Fitzhugh

For a few tense moments they stood, staring and unmoved, as if glued to the very spot. The apparition had disappeared within the hollow and it seemed to them that, perhaps after all, it was only a spirit they had seen hovering over the precipice. Suddenly Artie broke the spell.

"Spirits don't generally use ropes, do they? " he asked naively, as if he had been thinking it over seriously.