BAND OF AMMONIA, AND ITS OCCURRENCE IN THE SOLAR SPECTRUM. 
365 
enfeebled in each case. This is in accordance with the fact that all the brighter lines 
composing the central and secondary maxima as seen in the arc, some of which do not 
occur in the flame, are represented in the solar spectrum. 
The outcome of the comparison is to show that of the 260 band lines of ammonia in 
the region A 3450 to X 3286, there are about 140 which correspond with previously 
unidentified faint lines in the solar spectrum. About 100 of the remaining lines are 
obscured by lines for which metallic origins have been found, or fall upon lines which 
are too strong in the sun to be attributed entirely to ammonia, and the few which 
fail to appear in the sun are all of low intensity. 
It may be that additional solar lines are identical with lines composing the bands 
of ammonia which appear in the visible spectrum, but there are at present no 
experimental data for effective comparison. 
Description of Table V. 
The first five columns of the table give details of the ammonia band lines, showing 
the series to which they have been assigned, the intensities in the flame and arc, and 
the wave-lengths on the international and Rowland scales. The following three 
columns show the wave-lengths, intensities, and origins of solar lines occupying about 
the same positions as the ammonia lines, as given by Rowland. Between A 3363'5 
and A 3358'0 all the'Solar lines are tabulated, in order to show the large proportion 
due to ammonia in the region of the central maximum of the ammonia band. In the 
column of remarks, the following references have been adopted to avoid repetition. 
(1) Solar line probably not wholly due to ammonia, as indicated by excessive 
intensity. 
(2) Intensity of solar line probably over-estimated by Rowland, as inferred from 
a Higgs’ photograph. 
(3) Very close ammonia lines, which are only vaguely resolved in the 3rd order of 
the 10-foot grating. 
It should be noted that the resolving power in the case of the flame was less than 
that in the case of the arc spectrum. 
