here's a modern (non-functional) replica:

sadly the ivory commutator was missing from the original, and reverse-engineering one from a single photo with no look at the inside of the compensator coupling is basically impossible.
History lesson: Before the discovery of electrochemical 2:3-resonance in 1927, there was no way to drive the encabulation process automatically, and therefore no way to easily tune the asymptote. Because of that, the field was basically entirely theoretical, until the Sachri Reticulator.
Named after a Jean-Baptiste Sachri, a friend (some say lover) of the inventor, the Reticulator allows the operator to finely control the speed of a metal cylinder, in which is carved a groove that, if played in a phonograph, would produce two sine waves rising from 1Hz to 50kHz irregularly, varying in phase shift as they did so. The cylinder was instead "read" by three needles placed diagonally across the groove so that the distance between the outermost needles were 2/3rds of a wavelength out-of-phase with each other. The vibrations were then transferred into three irregularly-shaped plates inside the coupling seen on the image. The plates were then coupled to a 50cm long piece of ivory (the commutator), which held on its other end a seismograph-like drawing needle on a roll of paper. The plates' shapes had to be specially tuned to the composition of the ivory. By running through the frequencies on the cylinder, the operator could, by observing the line on the seismograph paper, find the point where the three vibrations cancelled out, and that is where the local asymptote is.
The Reticulator took the science of encabulation into the real world for the first time. The name of the inventor has been lost to time, but naming such an important device after his dear friend is surely the greatest act of love.
it was strictly planar, but as a first step that's huge. spline reticulation requires one more dimension. at a stretch you can scribe the silhouette of a spline on that plane.