Dew point observations from the Colaba Observatory, Bombay [Mumbai], India Monthly mean differences in dewpoint, based on morning and afternoon readings made over the period 1 January-31 December 1858 at the Meteorological Observatory at Bombay. Columns for the combinations of differences between Ronuld's, Daniell's and Regnault's hygrometers, Orlibar's readings, and Glaisher and Apjohn's formulae. Results for August-December using Regnault's hygrometer are not present, the instrument being out of order. Headed: 'Table shewing the monthly mean differences of Dewpoint for a.m and p.m. [6a.m., and 3p.m., added in pencil] by the different methods of observations and calculations during the year 1858'. 1859 [?]