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To some enterprising pioneers, the balloon afforded an unexcelled 
position for making panoramic photographs. Among others who designed 
and built their own aerial panoramic cameras was our unfortunate 
friend Triboulet, who, in 1-890, combined ideas and built an automatic 
panoramic camera to be carried skyward by a captive balloon (Figure 16). 
Following Prof. King’s Boston experience with J. W. Black, more 
than a score of air-minded photographers used his many balloons in 
unsuccessful efforts to get aerial photographs. It was 30 years 
later, in 1890, that the reason for so many failures was determined. 
Studying results of these early American experiments, W. N. Jennings, 
a Philadelphia photographer, concluded: 
"When the light of the sky floods the landscape, the quickest 
shutter speed is far too slow for a wide open lens and instan 
taneous plate." 
Jennings, accordingly, stopped down his lens, used a slower emul 
sion and a yellow color screen. In July, 1893, with King as his navi 
gator, Jennings obtained some truly remarkable views of Philadelphia 
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and its environs. His double-coated,* orthochromatic plates were 
small, but even when enlarged to 24 x 36 inches, the prints, as Jennings 
pointed out, had all the qualities of a rich steel engraving without 
a fuzzy line (Figure 17). 
The same year that Jennings was experimenting over Philadelphia, 
Hr. C. B. Adams, of Augusta, Georgia, obtained a patent on a "Method