Harry Houdini’s first onstage water escape was his milk can act, which he debuted in St. Louis, Missouri, on January 27, 1908. When other performers began copying his milk can escape trick, Houdini replaced the act with the “water torture cell” in 1912. pic.twitter.com/UUxzPOVHnc— Eric Colleary (@ecolleary) April 30, 2018
I expect this photo was taken in England during the cell's construction in 1911 or 1912. I'm afraid I don't recognize the man in the background, nor the man reflected in the glass.
This photo and the Milk Can poster are currently on display as part of the Harry Ransom Center's Vaudeville! exhibition that runs through July 15. Check out the official website for more details.
Thanks to Eric for sharing this fantastic image!