I'm starting with a remarkable photo of Mack Sennett surveying production at his Edendale studio from the confines of his "switching tower." This originally ran in the November 1918 issue of Photoplay, and I've I'd had a print quality copy at my disposal I would have put it in the book. However, I am displaying it here, and would love to hear from anyone who might have a copy of the original still (or any similar stills of Sennett in his tower) in their collection.
Incidentally, after looking at the details on the set, I was able to determine that the film in production on the open-air stage is the Paramount-Mack Sennett Comedy WHOSE LITTLE WIFE ARE YOU?, which was released November 17, 1918, and was filmed circa August/September of that year. This is the drugstore set from that Eddie Cline-directed comedy, which stars Charlie Murray, Mary Thurman, Baldy Belmont, Wayland Trask, Eva Thatcher and Alice Lake (with Marie Prevost and Phyllis Haver among the Sennett girls in smaller bits).
Compare the set, including counter and prop pharmaceutical goods on the shelves, with the below still from my friend Bob Birchard (which appears on p. 96 of my book):
This still features Heinie Conklin and Ben Turpin, who make a brief cameo appearance in the film (which is believed lost) as two nuts on a raft who float through the drugstore after it floods.
Wayland Trask, at right, was a gifted character performer who tragically died the same day this film was released, November 17, 1918, as a result of the Spanish flu pandemic that killed an estimated 50 million people throughout the world (and is eerily being echoed by the current epidemic, which like the 1918 outbreak is based on the H1N1 strain). This still captures Trask in his final film appearance, probably only a couple months before his death.
Incidentally, the caption for the top photograph reads: 'Mack Sennett in his "switching tower," from which he can overlook his entire studio. He can see Louise Fazenda and Charlie Murray going through the action for a scene; he can watch Mary Thurman as she registers the Sennett dramatic idea; and he can hear, too, the pantomimic turmoil that prove his station is not only a "see-all," but a "hear all" as well.'
Fazenda is not in this film (she had been co-starring with Murray earlier, but was now working with Chester Conklin). Mary Thurman may be the girl waiting her turn in the chair off-stage (she plays a customer who creates a love triangle between Charlie Murray and his son in the film Baldy Belmont). Marie Prevost (who plays a steam room customer) might be the girl with the short dress standing closer to the edge of the stage. The credited cinematographers on this film were Fred Jackman and his brother Floyd, and either might be on the camera platform (or another uncredited cameraman).