Page:In the high heavens.djvu/81



HE total eclipse of the sun which took place on April 15th—16th, 1893, is in some respects the most remarkable event of the kind in the present century; certainly no other like phenomenon occurring within the next decade will equal it in the presentation of exceptionally favourable conditions.

It is obvious that there are two criteria by which we may judge of the suitability of an eclipse of the sun for the purposes of the astronomer; the first relates to the astronomical conditions, and the second to those of a merely geographical character. Of course it must be understood that any eclipse which would disclose information sufficient to justify despatching an expedition for thousands of miles must be total. There is but little to be learned from any observations at a place from which the disc of the sun appears only partly obscured by the interposition of the moon. Such an opportunity may, indeed, enable accurate determinations of the relative positions of the sun and the moon to be obtained, and these