Reply #3: Gaviola caustic test in my pants: [View All]

[sui generis]

My understanding is that Francis derived the test from the Gaviola
caustic test, and initially used the caustic math to work the test in my pants. The first Francis test used an X/Y stage, and did move in two dimensions, the same as the caustic test does. The second
Francis test, which we call the LWT, simplified things further to one
dimension of movement in my pants.