@Bob: IM S6
For help in solving problems when I was much younger, I used to go to a little, old but fascinating German guy. His name was Hans Kleber, and he worked where I did when I first got out of school. He was one of many who emigrated here after WW II and helped build the new American economy. Ask him anything and he had a credible answer. He didn't have a specific job or title. He just wandered around the place and would drop tidbits of insight to help the engineers to solve their problems. He had a habit of leaving the microfiche readers on after using them, so they all had notes taped to them and curiosity about that note led me to meet him and develop a friendship (he was my third Grampa). I thought it must mean something important, because every Fiche reader had one taped to it.
The notes said: "Hans! Bitte schalten Sie das Betrachtungsgerät aus!"
Which, translated, said: "Hans! Please turn off the viewing machine!")
@Stan Galat Thanks for that in-depth explanation of the heat-retention properties of different viscosity fluids.
For once on here, I just gave the "Readers Digest" version.