moving stairway

Down the girl went, and as she fell, the contents of her pocketbook spilled out upon the moving stairway.
Penny Nichols and the Mystery of the Lost Key|Joan Clark
Penny, half way up the moving stairway, tried to save her from a hard fall.
Penny Nichols and the Mystery of the Lost Key|Joan Clark
By leaning back on the rope I walked up the slope as easily as if it were a moving stairway.
The Young Forester|Zane Grey
If Skyhigh Sam could see you now hed go and invent a moving stairway for the equator just for spite.
Roy Blakeley, Lost, Strayed or Stolen|Percy Keese Fitzhugh

He had not supposed that a moving stairway went further than one story, and the thought of riding to the sixth floor was bliss.
Sunny Boy in the Big City|Ramy Allison White

Origin of moving stairway