ON COMPOSITE PHOTOGRAPHY AS APPLIED TO CRANIOLOGY, 



By J. S. BILLINGS; 



AND ON MEASURING THE CUBIC CAPACITY OF SKULLS, 



By WASHINGTON MATTHEWS. 



READ APRIL 22, 1885. 



At the last annual ineetiug of the National Academy, we presented, through the courtesy of 

 Major Powell, a preliminary communication upon the application of the method of composite 

 l)hotography to the study of craniology. 



Experiments in this direction have been continued at the Army Medical Museum during the 

 past year, and we have arrived at what seems to be a fairly satisfactory method for centering succes- 

 sive skulls in a series, in order that the images of each may be properly superimposed in the 

 camera. This might be done in a great variety of ways; but the one u])on which we have settled, 

 the details of which have been worked out by Dr. Matthews, is as follows : 



The camera stand and "patent k^ver adjustment-gallery stand," for the object are leveled 

 with a spirit level and the tops of both stands are adjusted at exactly the same height. Two 

 flue black lines, one horizontal and one vertical, are drawn from margin to margin on the ground 

 glass focusing plate, intersecting in the exact center. On the object stand are placed two frames 

 on which intersecting threads are stretched, exactly parallel with the lines in the camera plate, 

 so that they may be covered by the latter when focused. Besides these cross lines there is a verti- 

 cal thread, stretched on a separate frame, lying in the same plane as the other vertical threads and 

 the vertical line on the camera plate. The craniopbore is placed on the object stand behind the 

 first or anterior frame at such a distance that the facial bones of the longest skulls will not interfere 

 with the cross threads. The second or middle frame — that which bears a vertical thread only — 

 is 22 centimeters behind the first frame and is, of course, behind the craniopbore. The third or 

 posterior frame — a vertical board with a central opening 16 centimeters square — stands 50 cen- 

 timeters behind the first frame; to its top attached by one margin, is a screen of black velvet, 

 which IS raised while the skull is adjusted and dropped while the exposure is made. The posterior 

 frame is fixed in its vertical position; the other two frames are attached to the stand by hinges, 

 and are lowered during the exposure. A giaduated rule is placed by the side of the craniopbore 

 and is photographed with the skull so that scale of each picture may at any time be ascertained. 



After making sure that the threads are properly adjusted to correspond with the lines on the 

 ground glass ])late, the sensitized [ilate is inserted, the cap put over the camera and the plate 

 cover withdrawn. A skull is put on the craniopbore and adjusted, the first and second fi-araes 

 are lowered, the velvet screen let oown, the cap removed and a fractional or partial exi)osure is 

 made, the time being regulated by the metronome. The cap is then placed over the lens, another 

 skull is adjusted on the craniopbore and another fractional exposure made, and so on until all the 

 skulls of the selected series have been photographed on one plate which is not removed from the 

 camera until the last exposure is complete. The focal distance is the same for each skull. 



Tlie plane and points by which the skulls of the later series have been adjusted are the Ger- 

 mau horizontal plane, the subnasal point, the supra-auricular point, and the maximum occipital 

 point. For the front, the rear, and the side views we adjust the German horizontal plane to cor- 

 respond with the plane of the horizontal threads, while the subnasal and maximum occipital 

 points (or the supra-auricular points as the case may be) are brought into the plane of the vertical 

 threads. In preparing for the front view we take sight on the horizontal plane and the subnasal 

 point from the front — i. e. the side next the camera — and on the occipital point from behind through 



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S. Mis. 154 14 



