The diurnal inequality is shown for " winter " and " summer " respectively.
He also found a marked diurnal variation, A being considerably greater between 3 and 5 A.M.
It is thus customary in calculating diurnal inequalities either to take no account of days on which there is an appreciable rainfall, or else to form separate tables for " dry " or " fine " days and for " all " days.
And intended to eliminate irregular changes, but they also to some extent eliminate regular changes if the hours of maxima and minima or the character of the diurnal variation alter throughout the year.
The result, if considered alone, inevitably leads to an underestimate of the average amplitude of the regular diurnal variation.