Page:Scientific Memoirs, Vol. 2 (1841).djvu/227

The farther calculation then gives:

${\begin{aligned}\delta &=\,+\;\,20^{\circ }\;28'\quad \log \omega =2.73907.\\i&=\,+\;\,66\;\;\,43\\\psi &=1387.6{\mbox{, or, in the unity commonly employed,}}\\\psi &=1.3876{\mbox{.}}\end{aligned}}$

29.

The following table contains the comparison of our formulæ, with observations at 91 stations in all parts of the earth. As the three maps from which we have taken the data for our calculation are intended to represent the phænomena for the most recent epoch, we have included in our comparison only very recent observations, and we have taken, by preference, observations at those stations where all the three magnetic elements were observed. We are not at present in a condition to demand that the observations should be strictly cotemporaneous, unless we would see our stock reduced to a very small number.