What are the points in good blackboard work? To be quite dogmatic, for the sake of brevity, good blackboard work is:
1. Simple. "Blackboard ingenuities, dissolving from acrostic into enigma, and from enigma into rhyme are not necessary" and they are harmful besides. They distract, distort, make dizzy. The best blackboard work has the fewest lines, the most unity in its variety, the least approach to anything like a maze.
2. Clear. The best blackboard work is that which is easiest to follow, hardest to forget.
3. Varied. Our stock symbols are worked to death. Is it right to use the cross as commonly as you would a letter of the alphabet? Find something new or give the blackboard a vacation. It is not necessary that there be a quarter hour on every day's program for blackboard work. Who has not spent a "bad quarter of an hour" when the "exercise" was perfunctory?
4. Descriptive. All maps and plans, sketches of roads and rooms, of mountains and rivers, are good, because they help us to form for ourselves the picture which we must see in order to grasp the meaning of the story. For example, we may illustrate the Mount of Transfiguration; first with four figures, then six, then four; the winding road to Emmaus, two figures—straight lines, merely—and a little farther on, a third; the upper room, its occupants represented by marks or initial letters. Anything is helpful that gives a notion of position, number, form, contrast, sequence, change.
5. Free, living, personal. The best blackboard work is that which is freest. Children are impressionists. For them the broad side of the crayon is better than the point; two strokes better than twenty.
The best blackboard work is that which grows before the children's eyes, which is made, not unveiled. Two minutes of rough sketching in the lesson hour is better than two hours of patient putting in of finishing touches beforehand.
The best blackboard work is that which is original, personal. That which is given in the "lesson helps" is just what you should not use. It is not yours. If it does not help you to find your own way, it is useless—and worse than useless, because it tempts you to borrow without inspiring you to create.
6. In fine, the mission of the blackboard, as of all picture-work, is to help us to see the truth in the world or the truth in our own selves by showing us a truth that is easier to see or that is nearer at hand than that which we would learn.
Like all picture-work, it fulfills its mission when it serves as a scaffolding, when it is kept subordinate. It fails when it obscures the truth, not helps to build it. False picture-work is anything that stands in the way of our seeing truth; as when we cannot see the woods for the trees—cannot see the Sunday-school lesson for the bizarre exhibitions on the blackboard.