factor, it being important that the tile be thin enough to be
reasonably light, but thick enough not to break easily or to let heat
through; that a level surface is desirable, both for the sake of
beauty and utility; and that some way must be found for pressing the
clay into shape. All of these ideas lie within their personal
experience and therefore call only for common knowledge and common
sense.

All or most of this part of the plan, including the correction of any
misstatements, could be made by the children with little or no help
from the teacher. Where their knowledge is more limited, however, she
should come to their aid, either telling or developing, as the case
required. For instance, she might possibly tell outright how much clay
each would probably need, also how the clay should be pressed into
shape; and develop the method of making sure of proper dimensions, of
square corners (or of roundness) and of a level surface.

This task in manual training is typical of lessons in general. In
their mastery there is always a procedure of some sort to be followed,
and now and then, at least, this procedure lies in whole or in part so
fully within the class experience that they should have the
responsibility of mapping it out. Sometimes in the lower grades such
work might occupy a whole recitation period; again, only a few
minutes. As the experience increases, this responsibility should
increase, so that the higher grades should often show children stating
the main questions to be considered in their lessons, without help,
just as they have long been in the habit of stating the main steps to
be taken in individual problems in arithmetic without aid. In very
many recitations children should have responsibility for rejecting
some of the answers and for accepting others. The writer is acquainted