On observation hours convenient to amateur meteorologists, and adequate for obtaining mean values by Saloman Moses Drach Reference Colonel [Edward] Sabine’s Toronto report, and Drach’s papers contained in the Philosophical Magazine regarding Plymouth ad Leith observations which showed ‘if the barometer or thermometer be observed four times a day at six-hour intervals, commencing at any convenient hour, the result of an annual series would all but equal the mean of one or two hourly observations’. Includes a table depicting the sums of observations at Toronto and Greenwich for temperature, vapour pressure, gaseous pressure, and force of wind. April 1845