186 ©. A. Young—Spectroscopic Observations upon the Comet. 
(3.) The spectrum of the tail appears to be a continuous spec- 
trum overlaid by a banded spectrum, the same as that of the 
coma. The bands in the spectrum of the tail were followed to 
a distance of about 20’ from the head, on June 29 and July 1. 
he continuous spectrum ceased to be visible before the bands 
were entirely lost sight of, using a slit wide enough to unite 
the b’s into one band. 
(4.) The spectrum of tne coma shows only three bright bands 
with a faint continuous spectrum connecting them. No other 
bands could be found, though the continuous spectrum could be 
followed from about half way between C and D, to above G. 
The Fraunhofer lines could not be seen either in the spectra of 
the nucleus or of the coma. 
While the comet was brightest, the bands, especially the up- 
per and lower ones, were very ill-defined, so much so as to in- 
terfere with satisfactory measurements of position. After July 
1 the definition became better. 
.) The coma spectrum was very carefully compared with 
the spectrum of the Bunsen burner flame, with the spectra of 
Geissler tubes containing CO, CO, and ether vapor, and also 
with the Hae spectrum of magnesium and air. The wave 
length of the less refrangible edges of each of the three bands 
was carefully determined by micrometer measures, on June 29, 
d 12. 
spectrum and the spectra of the Geissler tubes was striking. 
The lower of the three comet bands was the only one which 
was even approximately coincident with any band of the tube 
spectrum. 
(6.) The measurements on the evenings named give the fol- 
lowing numbers for the wave-lengths of the bands, viz: 
Lower edge of lower band, A = 5629" + 40 
Lower edge of middle band, A = 5164°9 + 0°6 
Lower edge of upper band, = 4740° + 2°9 
The lower band was much the most difficult to deal with. 
The maximum of brightness seems to be, not at the edge of the 
band, but a little way up, and this perhaps may explain the 
fact that I obtained 5564 in the case of Hartwig’s comet (while 
Von Konkoly obtained 5610—a much better result). Dr. 
Watts (Nature, vol. xx, page 28) gives 5634°7, 5165°3 and 
4739°8 as the wave-lengths for the corresponding bands in the 
spectrum of the Bunsen flame. 
(7.) The middle band, on June 29, July 1, 2, and 38, showed — 
