And one may, in this instance, see what gave occasion to the rule, that a definition must consist of GENUS and DIFFERENTIA; and it suffices to show us the little necessity there is of such a rule, or advantage in the strict observing of it.

Indeed, all astronomical observing seems to be so fitted.

It must be admitted that the gunners on the whole made excellent shooting, and if they did not destroy their target, or even make him turn back, they fulfilled the almost equally useful object of making him keep so high that he could do little useful observing.

" The following letter from Miss Mitchell, though written at a later date, gives an idea of the practical observing done by her classes:

It must be admitted that the gunners on the whole made excellent shooting, and if they did not destroy their target, or even make him turn back, they fulfilled the almost equally useful object of making him keep so high that he could do little useful observing.