NavList:

Isn’t there a tendency for surface tension to pull a light mirror to the edge of the container?
I found two problems with my “wet” AH experiments at 53N in winter.  Unless dead calm, the wind causes ripples on water, and the height of the edges of the container, restricts the minimum value of Hs which can be recorded.  Thick, black engine oil allows use in slightly stronger winds, but carrying the near full container back into the house risks a dreadful calamity.  That’s why I went for a good strong mirror on a solid adjustable base.  I wonder how people like Tycho Brahe worked.  I suspect they measured down from the vertical and made their gear giant size.  Dave