Herschel, John F. W. (John Frederick William), Sir, 1792-1871 · London : Longman, Rees Orme · leaf 162
stance of the point whose level we wouldknow from the surface of an equilibrated ocean: only inthe one case it is an ocean of water; in the other, of air.In the one case our sounding line is real and tangible;in the other, an imaginary one, measured by the lengthof the column of quicksilver the… … continent, of which the portion ABC projects above thewater, but is covered by the oil, which also floats at anuniform depth on the whole ocean. Then if we would knowthe depth of any point D below the sea level, we letdown a plummet from F. But if we would know theheight of B above the same level,…
Astronomy
Internet Archive · York University Libraries · Public Domain Mark 1.0. Free to use for anything.
