That was a year ago. I've since built a device that can hold the resonance steady for 11 minutes. I've made three trips. The "City of the Gilded Gears" is a nightmare of Victorian architecture and alien geometry, lit by a bronze sun. The "Office of Weights and Measures" is run by creatures that look like asthmatic, three-legged calipers.
But Table 56 is different.
Step one was to cast a specific bismuth alloy ring, exactly 56.234 mm in diameter. Step two was to cool it to 4 Kelvin while bathing it in a 0.4 Hz alternating magnetic field. Step three was to ignore the official ASTM table and use his coefficients. astm table 56