A capillary tube of radius r is immersed vertically to a depth h₁ in the liquid of density ρ₁ under test. The pressure gρh required to force the meniscus down to the lower end of the capillary and to hold it there is measured. If h₁, and consequently h, be varied, a plot of ρh against (h₁ - r/3) gives a straight line from whose slope and intercept the surface tension and the density of the liquid may be inferred.