This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
PSM Junction of wheel pit tunnel of the niagara paper co. Junction of wheel pit tunnel of the Niagara Paper Co archive org Popular Science Monthly Volume author PDold Extracted image from book to grayscale cropped whitespace ineuw archive org Popular Science Monthly Volume Popular Science Monthly illustrations Hydroelectricity