274 



and some columns are left blank to show that they are still desirable." 

 The pentads or decades to be used in such a table as this should 

 always be those introduced by Dove, the limiting dates of which are 

 as given in this table; the twelfth pentad of the ordinaiy year has 

 five days, but that of the leap year has six days, so that the limiting 

 dates are alw^ays as here given, viz, from February 25 to March 1, 

 inclusive. The data given by Descroix in the Annuaire for 1 890 con- 

 sist of the mean values for the respective pentads. From these I have 

 constructed the sum totals from January 1 to date, which are needed 

 in agriculture, and which are still more easily obtained when we have 

 the original tables of observations at hand, by simply taking the 

 sums in a continuous series and avoiding the labor of computing the 

 means. From such a table of sum totals w'e obtain the sum between 

 any two dates by subtracting the sum for the earlier from that for the 

 later date. 



a The omitted columns are: (1) Sunshine; actual duration. (2) Actino- 

 metric degrees; actual daily average. (3) Ratio of actual actinometric degrees 

 to the maximum possible daily average. (4) Soil temperature at the surface. 

 (5) Soil moisture. (U) Percentage of saturation. 



