Page:Popular Science Monthly Volume 52.djvu/199

Rh {|width=135px Compare upper and lower views of the film. This graphic method should theoretically be applicable to insects and animals as well. as to plants. In practice, however, it can be successfully applied only to the lower and the higher forms of animal life. On the one hand, we could picture the growth of certain lowly organisms in the border land between the animal and vegetable worlds; on the other, we could portray the development of a child, or even the life changes of a human being from childhood to old age. Pictures of the latter class may evidently be taken at daily intervals; uniformity in position and expression, as well as in the clothing or drapery of the subject, being essential requisites to success in all such cases.
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In dealing with subjects of this nature we must take into account the inevitable deterioration of the sensitive films through lapse of time. It will become necessary, in fact, to use shorter films whenever the negative series is much prolonged. Such films could be treated separately, and afterward joined together so as to form one long strip—a procedure involving only the exercise of a little care and the use of some celluloid solution. From this composite negative film a single uniform roll of pictures would ultimately be obtained by the usual process.

The application of this method to outdoor objects will in general be greatly restricted, owing in part to the variable light and partly also to the influence of wind and weather. Some picturesque effects could, however, be obtained by photographing natural scenery under varying angles of solar illumination—especially in mountainous regions and near the time of sunrise or sunset, when the most striking changes would be manifested. Seasonal variations, too, might be illustrated by depicting scenery in a forest from day to day for months in succession. Owing to the gradual nature of