] 58

THE MOON’S CHANGES

here enter, because the subject would thus becomean exceedingly wide one, while in reality there islittle importance in the relations thus involved, sincein the arctic regions there are no harvesters to bebenefited, nor is hunting there pursued in the nighthours.

But we must now take into account the circum-stance that the moon moves on an orbit somewhatinclined to the ecliptic. It will, in the first place, bemanifest that if the position* of the plane in which

* I use this word to indicate not the actual place of the planein question, but the manner in which it is posed in space. Thusthe position of the earth’s equator-plane would, according to thisusage of the word, be described as identical (neglecting precession)throughout the year, the position of the earth’s orbit-plane identicalyear after year as the sun moves onward with his family of dependentorbs through space, the position of the plane of the Saturnian ringsidentical throughout the Saturnian year, and so on. A discussionoccurred a year or two ago, in the pages of a weekly journal, as tothe proper word to indicate this particular relation, and 1 advocatedthen the use of the word “ position ” as on the whole the most suitrable. The question is one to which my attention has been particu-larly drawn, because it has chanced that repeatedly in my writingsI have had to deal with this feature ; and I have found no word soreadily understood in this particular sense as the word “ position.”At the same time I must admit, first, that the word is not whollyfree from objection, and secondly, that several mathematicians, towhose opinion I feel bound to attach great weight, are opposed toits use in this sense. Unfortunately they suggest no other term.It appears to me that the objections to the use of the word “ posi-tion ” in the sense in question are precisely parallel to those whichmay be used against the word “ direction ” as applied to lines. Ifind, moreover, that Herschel, Grant, and other writers, use theword position as I have done, being apparently forced so to use it