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The rapid appearance of one after another edition of a text-book indicates the high regard in which it is held by professional teachers.
This work by Professor Wood is not an exception to this statement, for there is to-day no other work that is more generally popular. In this there is found a good reason in the author's thoroughness in his descriptions, and in his clear presentation of all that is definitely known of the subjects treated. So well is the work known that an exhaustive review is now entirely out of place.