y, I want to teach you the difference between concave and
convex: the under part of the curve is concave and the upper part of
it is convex. Then say, I shall now take the letter away, and wish you
to shew me concave and convex on one of your fingers; when they will
bend the forefinger and point them both out on it. Go on with the
other letters in the same way: shew them the vowels after the
consonants and analyze each one. For example, A is formed of two
inclined lines and a horizontal line to join them in the centre; and
the top of that letter is an acute angle, and were a line placed at
the bottom it would be a triangle. A brass letter may be moreover
shewn to be a substance: its properties may be described as hard,
smooth, bright, &c., and its coming from the mineral kingdom may be
noticed, and thus the instruction may be indefinitely varied.

The _power_ of letters may then be pointed out. Ask them to spell M R,
and they will give you the sound of R, or something like it, and so
in reference to other letters. But place the A against the M as it
appears in the figure, and you may teach them to say A, M, AM; and
thus all the way down the left side of the row of consonants. If then
you carry the vowel down on the other side of them, you will change
the lesson, and by such means go on almost _ad infinitum_. Double rows
of consonants may be placed with a vowel between them, and when well
practiced in this, they will ask for the vowel to be omitted that
they may supply it, which they will do very readily and with great
pleasure, while there is a tasking of the mind which cannot but prove
beneficial.

Again, turn the frame with the balls round, so that the wires are
perpendicular instead of horizontal, raise a ball gently, and say, To
ascend, ascending, ascended; let it fall gently, saying, to descend,
descending, descended; with a little explanation these words will then
be understood, and others may be taught in the same way. To fall,
falling, fallen; to rise, rising, risen; to go, going, gone, will
readily occur, and others will easily be supplied by the ingenuity of
the instructor. The frame may also be applied to _grammar_.

It is to be used as follows:--Move one of the balls to a part of the
frame distinct from the rest. The children will then repeat, "There
_it_ is, there _it_ is." Apply your finger to the ball, and set it
running round. The children will immediately change from saying,
"There _it_ is," to "Ther