Sextant, Arc Drum Worn to Bone

This is a Heath and Company sextant, maybe 1920s, pulled from a navigation school's surplus shelf and laid flat on the bench so the arc faces up. I shot it with the 4x5 and a long bellows extension to get the degree graduations filling the lower third — you can see where the silver has gone dull at the most-used readings, the metal honest about where someone's thumb rested ten thousand times. The micrometer drum is the whole story here: whatever it once measured is gone, but the wear knows exactly where the sea was.