Trans Acad. Sci. of St. Louis, Vol. XI. 



Plate V. 



SflflBF "■' 1 ^w^|'i 



*r ^. sx oo 



x- - o 



7. Exposure, 3,200. Illumination, 3. 



T ~ too 



8. Exposure, 3.200. Illumination, 100. 



DIRECT AND REVERSED PHOTOGRAPHY. 



