An estimate of the temperature of different latitudes
by
From records of Irish weather covering forty-one years, Kirwan worked out a system of probabilities with a view to forecasting the weather for seasons ahead. his predictions were more often right than wrong and were much valued by farmers. His concept of air masses-- which he termed 'polar' and 'equatorial,' 'supra-marine' and 'supra-terrene' anticipated modern classification.