The formal title of this puzzle book is The Sherlock Holmes Escape Book: The Adventure of the London Waterworks by Ormond Sacker. Yes, genre labels are always terrible; "escape book" is what people are calling them these days. And yes, "Ormond Sacker" is a pseudonym. The puzzle and text were created by David Whiteland, who created the Planetarium web puzzle that I reviewed... oh, jeez, I wrote that review exactly twenty years ago.
At any rate! You are Holmes, investigating dastardly goings-on at the Kew Bridge Waterworks. (A historical location, now the London Museum of Water and Steam.) Watson follows you around with his revolver and his reliably dunderheaded commentary. Okay, that's not fair. He points out clues as often as he misses them, and he tends to roll his eyes at your snottiness when you're not looking.