Hoover Dam turbine, c. 1933.
https://diqn32j8nouaz.cloudfront.net...e_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...059#post172055
https://www.homemadetools.net/forum/...158#post168849
https://www.homemadetools.net/forum/...134#post161016
https://www.homemadetools.net/forum/...758#post163556
https://www.homemadetools.net/forum/...447#post162153
