ABSTRACT. ABSTRACT. The manometer example in Wittgenstein's Philosophical Investigations § 270 is notoriously difficult to interpret; ironically, in one sense, because it is supposed to clarify by concrete analogy Wittgenstein's abstract remarks about the impossibility of private language. There is no standard interpretation of the manometer passage, partly because Wittgenstein's remarks have been found so difficult to explain that they are often ignored. Where interpretations are ventured, they disagree pointedly and can be seen either to conflict with or fall short of adequately explaining the manometer.