JF Ptak Science Books Post 1095
Even though this woodcut looks a bit odd, it hides the fact that it is a superb device for its mechanical purpose–mapping the head for hatters. Certainly most folks would look at this image and have their imaginations decide many more and creative (but not-real) uses than that. But the fact remains that it was an ingenious instrument that 
could (can!) produce an excellent contour map of the head. It is difficult to imagine a more accurate mechanical method of performing this task this beautiful device. (The device would be place on the head like a hat, fitted down snug causing the head’s contours to extend the spokes, producing an image of the head’s shape like the map on the upper left inset. Very cool.) And I love the use of so many (clean) screws rimming the base of the mapper.
Then on the other end of the spectrum of antiquarian steampunk headware:
was this simple umbrella to protect the hat. It reminds me of the utility of a portable pocket-sized mustache guard. I wonder if you were expected to carry an umbrella to protect the rest of your body? Or another to protect the umbrella that was protecting the hat umbrella? (Tortoises all the way down….) Still, though, this is a great drawing with applications far beyond the reach of a simple hat protector.
