ON A TABLE OF STANDARD WAVE LENGTHS OF THE SPECTRAL 1-1 M S. 
m 
121 
Co. (2) . . . . 
" (4) . . . . 
'* (6) . . . . 
« (4) . . . . 
Mean 
C 
Ji 
h ....... 
C 
Mean 
General mean 
Correction to standard 
t 
7023 











6.7G 
O 
+ 6.702 
i 
027 
8.982 
3.071 
8,954 
8.01*8 
8.080 
3.939 
3.DU1 
3.070 
8.077 
6.762 
+ 2.7^5 
7010 
it;.2<>i 
10 202 
lO.uJO 
T).2;k) 
-L 
lO.auG 
16.^32 
16.810 
lO.HiiO 
1G.3UI 
I6.:;i2 
10.309 
6,7(>2 
-9.517 
TABLE III. 
SIX-INCH CONCAVE GRATING. 
Orders of 
Spectrum. 
(1) 
No. 
i 
of readings 
2ob. 
2ob. 
4ob. 
Grating 14,436 lines to the inch, and 21 J feet radius, 
Observations made iu 1884 by Rowland. 
4691.590 
4691.500 
4691.590 
4690.326 
7u27.778 
7027.778 
Hence 
4690.96: 
« = 7on0.556 
3 A-2f = 11.774 
7040.092 
(2) § 
4ob. 
Hence 
4215.656 
Be- 
o 
P 
6322.906 
15.900 
(3) f 
(4) % 
(5) § 
(6) f 
(7) I 
10 ob. 
10 ob. 
4ob. 
10 ob. 
7ob. 
Hence 
4376.101 
6563.042 
2 5-3/=4.193 
4376.104 
Hence 
6563.042 
2 ^-3/= 4.220 
6564.423 
6884.082 
4590.10Q 
4588.364 
6322.879 
4215.655 
Hence 
3e-2i? 
15.951 
6322.879 
4215.651 
Hence 
$e-2p 
16.939 
