Item 204 - Letter from Francis Baily

37 Tavistock Place - Would WW restate the formula he suggested 'for determining the specific gravity (reduced to a vacuum) of hollow bodies, not hermetically sealed'. FB has received a letter from Frederick Bessel in response to FB's 'remarks on his experiments with hollow cylinders (not hermetically sealed) which has rather staggered me; & makes me fear that I may myself be in error'. Although FB's 'case is not exactly the case in point: but is, in fact, one still more erroneous: - at least in my opinion'. Could WW give his opinion [an extract of FB's letter to MB is enclosed].