The present Note deals with a modification of the method described in vol. li, pp. 118-126.

The method suggested in the original Note necessitated the finding of the values of the first, second and third continuous summations of the data to be valued. These summations in some cases were laborious, and the object of the present contribution is to demonstrate how the arithmetical work can be curtailed without material loss of accuracy, firstly, by reducing the number of continuous summations, and secondly, by summing in quinary groups instead of by individual terms.