In the third place, many a lesson is side-tracked because the scholars are not on the side of the teacher. Of course, when the two parties are at cross-purposes, things run no more evenly than they would if the engineer of a train were out of touch with his crew. The teacher must get up an _esprit de corps_, a class spirit, or his class will be perpetually flying off from him on a tangent. His scholars must be interested in him, if they are to be interested with him. He must draw them to himself, or they will never pull together. Friendship in his crew must take the place of authority in the railroad crew; and the more friendship, the less side-tracking. In the fourth place, there must be frankness of speech. A misplaced switch on a railway, if it provoked no further collision, would at least provoke a clash of words. There is no reason why, if a question is too far aside from the main purpose of the lesson, the teacher should not frankly say so. He may lay it away in his mind for later discussion; he may promise to talk it over after the session; but no fear of being thought incompetent, or unsympathetic, or arbitrary, should induce him to turn aside from his one purpose. The wise teacher will make many exceptions, of course, to every rule; but nevertheless, a rule of the wise teacher it must be, to say to every irrelevant question, kindly and tactfully, yet firmly, "Get thee behind me." For the half-hour is all too short. The impressions made are all too confused. The instruction given is all too fragmentary. However wise and earnest the individual moments may be, there is danger that the half-hour may pass into oblivion at once, unless these individual moments have been wise and earnest to some single, distinct end. There is a place for switches in our Sunday-school lesson. The train must be made up. Side excursions must often be made. There are sundry connecting lines whose cars must be switched in. But in genuine Sunday-school railroading there must be no delay upon side-tracks. Let all teachers, as far as possible, run express. Chapter XXVI The Problem of the Visitor The analogy for the class-building of some teachers is the arch. Every scholar is needed in his place, or the class-work collapses; and of course there is no room for a visitor. The analogy for the true class is the electric circle. Join hands all around, and ever room and electricity for one more. I do not mean to imply that the visitor is not a problem. He is an intrusion on your familiar little group. He is a foreign and constraining element. He is a problem, however, that you cannot get rid of, but must solve. Utilize the visitor. Go to work in such way as to transform him into a scholar; or if circumstances forbid that, at any rate win from his visit fresh interest and inspiration for the class. Every visitor is an angel of opportunity, entertained--how often!--unawares.