proportion of them to understand the subject.  So, if a teacher is explaining to a class in Grammar the difference between a noun and verb, the explanation would do as well for several hundred as for the dozen who constitute the class, if arrangements could only be made to have the hundreds hear it; but there are, perhaps, only a hundred pupils in the school, and of these a large part understand already the point to be explained, and another large part are too young to attend to it.  I wish the object of these remarks not to be misunderstood.  I do not recommend the attempt to teach on so extensive a scale; I admit that it is impracticable; I only mean to show in what the impracticability consists, namely, in the difficulty of making such arrangements as to derive the full benefit from the instructions rendered.  The instructions of the teacher are, in the nature of things, available to the extent I have represented, but in actual practice the full benefit can not be derived.  Now, so far as we thus fall short of this full benefit, so far there is, of course, waste; and it is difficult or impossible to make such arrangements as will avoid the waste, in this manner, of a large portion of every effort which the teacher makes.

A very small class instructed by an able teacher is like a factory of a hundred spindles, with a water-wheel of power sufficient for a thousand.  In such a case, even if the owner, from want of capital or any other cause, can not add the other nine hundred, he ought to know how much of his power is in fact unemployed, and make arrangements to bring it into useful exercise as soon as he can.  The teacher, in the same manner, should understand what is the full beneficial effect which it is possible, in theory, to derive from his instructions.  He should understand, too, that just so far as he falls short of this full effect there is waste.  It may be unavoidable; part of it unquestionably is, like the friction of machinery, unavoidable.  Still, it is waste; and it ought to be so understood, that, by the gradual perfection of the machinery, it may be more and more fully prevented.

Always bear in mind, then, when you are devoting your time to two or three individuals in a class, that your are losing a large part of your labor.  Your instructions are conducive to good effect only to the one tenth or one twentieth of the extent to which, under more favorable circumstances, they might be made available.  And though you can not always avoid this loss, you ought to be aware of it, and so to shape your measures as to diminish it as much as possible.

We come now to consider the particular measures to be adopted in giving instruction.

The objects which are to be secured in the management of the classes are twofold: 

1.  Recitation. 2.  Instruction.