Vintage Science Images from the Smithsonian: it’s MAD, MAD, I tell you! 
In my ongoing quest for more examples of things I don’t understand, but do admire*, I’ve stumbled on this collection of vintage science images from the Science Service of the Smithsonian National Museum of American History.
Wonderful old photographs of lab equipment and industrial machines of all sorts!
There’s also this collection, which I found first and which (I think) is separate from the subjects menu at that first link.
These collections are a terrific resource for visualizing nearly plausible mad science labs!
* This is, in fact, a very large category.
