are still rich possibilities along this line.  The photoplay has hardly come to its own with regard to these secondary emotions.  Here it has not emancipated itself sufficiently from the model of the stage.  Those emotions arise, of course, in the audience of a theater too, but the dramatic stage cannot embody them.  In the opera the orchestra may symbolize them.  For the photoplay, which is not bound to the physical succession of events but gives us only the pictorial reflection, there is an unlimited field for the expression of these attitudes in ourselves.

But the wide expansion of this field and of the whole manifoldness of emotional possibilities in the moving pictures is not sufficiently characterized as long as we think only of the optical representation in the actual outer world.  The camera men of the moving pictures have photographed the happenings of the world and all its wonders, have gone to the bottom of the sea and up to the clouds; they have surprised the beasts in the jungles and in the Arctic ice; they have dwelt with the lowest races and have captured the greatest men of our time:  and they are always haunted by the fear that the supply of new sensations may be exhausted.  Curiously enough, they have so far ignored the fact that an inexhaustible wealth of new impressions is at their disposal, which has hardly been touched as yet.  There is a material and a formal side to the pictures which we see in their rapid succession.  The material side is controlled by the content of what is shown to us.  But the formal side depends upon the outer conditions under which this content is exhibited.  Even with ordinary photographs we are accustomed to discriminate between those in which every detail is very sharp and others, often much more artistic, in which everything looks somewhat misty and blurring and in which sharp outlines are avoided.  We have this formal aspect, of course, still more prominently if we see the same landscape or the same person painted by a dozen different artists.  Each one has his own style.  Or, to point to another elementary factor, the same series of moving pictures may be given to us with a very slow or with a rapid turning of the crank.  It is the same street scene, and yet in the one case everyone on the street seems leisurely to saunter along, while in the other case there is a general rush and hurry.  Nothing is changed but the temporal form; and in going over from the sharp image to the blurring one, nothing is changed but a certain spatial form:  the content remains the same.

As soon as we give any interest to this formal aspect of the presentation, we must recognize that the photoplaywright has here possibilities to which nothing corresponds in the world of the stage.  Take the case that we want to produce an effect of trembling.  We might use the pictures as the camera has taken them, sixteen in a second.  But in reproducing them on the screen we change their order.  After giving