510 REPORT—18638. 
April 18. 
Before starting the solar spectrum extends from B to nearly H, and the 
sky spectrum from B to G; these lines were quite the limit. 
At 1" 20™ p.m., at 3555 feet. The spectroscope was directed to the sky 
near the sun; G was very clear; can see H and far beyond. 
At 1" 21™ 10° p.m., at 43892 feet. Very mary lines in the sky spectrum ; 
the line B is clear. 
At 1" 27™ p.m., at 7764 feet. Sky spectrum from B up to A. 
At 15 27™ 308 p.m., at 7764 feet. Beyond H and A in the sky spectrum, 
under and near the sun, lines beautifully defined; requires great change of 
focus to see A and H. When spectrum is directed at some distance from the 
sun can see B and several lines beyond. 
At 1" 29™ p.m., at 10,020 feet. Sky spectrum short. 
At 1" 53™ p.m., at 20,163 feet. Examined slit of apparatus; all seems right. 
At 2°12” p.m., at 21, 646 feet. No sky spectrum ; no lines. 
At 2" 15™ p.m., at 22,041 feet. Solar spectrum extended a good way 
beyond H at the violet end. On passing from the sun the spectrum shortened, 
and G was the limit; this was soon lost and the spectrum shortened rapidly, 
At 2" 15™ p.m., at 22,041 feet. On approaching the sun again the yellow 
first appeared, and when very near the sun on all sides the spectrum was 
perfect, increasing in length the nearer it approached the sun; and when a 
beam of light came from the sun itself the whole spectrum was visible, and 
many lines between A and a andaand B. On passing from the sun the 
same phenomena were repeated as before; and when the sun again came 
round, from A to a good way beyond H was examined, and every line was 
seen that was visible from the earth, and a good many more. 
June 26. 
At the highest point the sky spectrum was the same as on the earth. 
July 11. 
At 5" 28™ p.m., at 3581 feet. Sky spectrum from B to G seen. 
DIFFERENT APPEARANCES OF THE GAs. 
March 31. 
At 4" 41™ p.m., at 13,070 feet. Gas very thick. 
At 4" 47" p.m., at 17,060 feet. Gas issuing from the neck of the balloon. 
At 4" 48™ p.m., at 17,451 feet. Gas yellow and opaque. 
At 5" 57™ p.m., at 13,614 feet. Gas very clear. 
April 18. 
At 1" 38™ p.m., at about 15,000 feet. Gas clear. 
At 1" 54™ p.m., at 20,163 feet. Gas clear. 
June 26. 
At 1" 33™ p.m., at 17,242 feet. Gas seen rushing out of the balloon in 
volumes. 
July 21. 
At 4" 55™ p.m., at 2095 feet. Gas very cloudy. 
At 4" 59™ p.m., at 2550 feet. Gas getting clearer. 
