ta’ ALT oung—Bright lines of the Chromosphere. 
The second column gives the position of the line upon the 
scale of Kirchhoff’s map—determined by direct comparison 
with the map at the time of observation., In some cases an in- 
terrogation mark is appended, which signifies not that the exst- 
ence of the line is doubtful, but only that its precise place could 
not be determined, either because it fell in a shading of fine 
lines, or because it could not be decided in the case of some 
close double lines which of the two components was the bright 
one; or finally because there were no well marked dark lines 
near enough to furnish the basis of reference for a perfectly 
accurate determination. 
The third column gives the position of the line upon Ang: 
strom’s normal atlas of the solar spectrum. In this column 
occasional interrogation mark denotes that there is some doubt 
as to t fA 
Kirchhoff’s.. There is considerabie difference between the two 
sometimes diffigult, and makes the atlas of Kirchhoff far supe 
rior to the other for use in the observatory. anak 
he numbers in the fourth column are intended to deno | 
the percentage of frequency with which the corresponding 
lines are visible in my instrument.. They are to be regarded . 
only roughly approximative; it would of course require a ‘vind 
longer period of observation to furnish results of this 
worthy of much confidence. 
The sixth column contains the symbols of the chemical yen 
stances to which, according to the maps above referred t0, 
rin. 
than one substance coincide with each other and with a decide 
the solar spectrum so closely as to make it impossible to 
In the seventh and last column the letters J., L. and R. i. 
note that to pe Pogues é the line indicated has 
by one or the other of these keen and active observ™ 
but if so I have as yet seen no account of such determim 
