There was no company name, no tiny print in the corners. Just this equation, whose terms do not look familiar to me. Even the number 0.622 looks unfamiliar, and I don't know what "he" might stand for here --- heat? Some sort of differential equation about heat?
As seen in Gare du Nord, Paris, November 24 (still there December 2).
This post's theme word is alembic "an alchemical apparatus for distilling." (From Miéville's Kraken (p.175), of course, as he is the source of all eldrich vocabulary.) The alembic equation yielded no clarity to the problem.