But all these effects, audible or visible, may be resented as mere stage-tricks, unless they really belong where they are put, unless they are intimately related to the main theme of the play, and unless they are really helpful in evoking and sustaining the current of sympathy. They are excrescences if they exist for their own sake only; they are still worse if they interfere with this current of sympathy, if they distract attention to themselves. The stage-manager must ever be on his guard against the danger of sacrificing the major to the minor, and of letting some little effect of slight value in itself interfere with the true interest of the play as a whole. At the first performance of Mr. Bronson Howard's 'Shenandoah,' the opening act of which ends with the firing of the shot on Sumter, there was a wide window at the back of the set, so that the spectators could see the curving flight of the bomb and its final explosion above the doomed fort. This scenic marvel had cost time and money to devise; but it was never visible after the first performance, because it drew attention to itself, as a mechanical effect, and so took off the minds of the audience from the Northern lover and the Southern girl, the Southern lover and the Northern girl, whose loves were suddenly sundered by the bursting of that fatal shell. At the second performance, the spectators did not see the shot, they only heard the dread report; and they were free to let their sympathy go forth to the young couples. Here, once more, as so often in the art of the stage, suggestion was far more potent than any attempt to exhibit the visible object. The truth of this axiom was shown in the third act of the same play, during its earlier performances, when the playwright with the aid of a scant dozen soldiers was able to suggest all the turmoil and all the hazards of a battle only a little removed. At later performances, the author allowed the attempt to be made actually to represent certain phases of a retreat, with horse, foot and artillery on the stage all at once; and altho the stage-management was excellent in every way, perhaps the total effect was less than when the far larger possibilities of a great battle had been merely suggested to the spectators, their own imaginations evoking the possibilities of war more completely than any stage-manager could set it before them.