form, and they will say, A curved line.  If they are then asked how they may know it is D, they will say, Because it is made of a perpendicular line and has a curved line behind.  Further information may then be given.  Turn the D letter up thus [Illustration:  The character D turned on its side], and say, 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 “There it goes, there it goes.”