One is the ceaseless activity of the children.

The other is the bright and happy look on every face.

In too many elementary schools the children are engaged either in laboriously doing nothing,--in listening, for example, with ill-concealed yawns, to _lectures_ on history, geography, nature-study, and the rest; or in doing what is only one degree removed from nothing,--working mechanical sums, transcribing lists of spellings or pieces of composition, drawing diagrams which have no meaning for them, and so forth.

But in this school every child is, as a rule, actively employed.

And bearing in mind that "unimpeded energy" is a recognised source of happiness, the visitor will probably conjecture that there is a close connection between the activity of the children and the brightness of their faces.
That the latter feature of the school will arrest his attention is almost certain.