^{page 218 note *} If the terms are arranged in the reverse order the corresponding condition is that λ⁽ⁿ⁾ and V⁽ⁿ⁾ have the sign of (-)ⁿ.

^{page 218 note †} An illustration only, for in this particular problem it is better to use Lever's method (J.I.A., vol. lii. p. 171) of equating a_x to and interpolating for n. In our example this gives almost an exact result. But this or a similar method is not available for functions in general.

^{page 218 note ‡} More generally we may use log₁₀ (K +mantissa of log₁₀V), where K is a small integer chosen to quicken the convergence of the differences.