, in passing from one term to the other, are of the same sign, are the strongest, and those in which they are of opposite sign the weakest. These intensity relations are of great assistance in picking out the multiplets.
“Combinations between terms of different systems (consistent with the foregoing rules) often occur. Such lines are usually, though not always, faint....
“The serial number
of the term (which is equivalent to the total-quantum number) plays quite a subordinate rôle, being of importance only when series formulae have to be calculated. An extensive analysis of a spectrum is possible without it, though determination of the limits of the series, and the ionization potential, demands its introduction.”
III. MATERIAL USED IN CHAPTER VIII
THE line intensities quoted in [Chapter VIII] were derived from the spectra of the stars enumerated below in [Table XXXII]. Successive columns contain the Draper class, the name of the star, the Boss number, the visual apparent magnitude, and the reduced proper motion H. The stars within each class are arranged in order of right ascension.
[TABLE XXXII]
| Class | Star | Boss | m | H | Class | Star | Boss | m | H | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
 |  | Cen | 3054 | 3.3 | 1.7 |  |  | Vel | 2723 | 4.1 | 5.1 |
 |  | Phe | 148 | 4.5 | -0.5 |  | Sgr | 4832 | 2.7 | 0.0 | |
 | For | 474 | 4.7 | 0.1 |  | Gru | 5880 | 3.7 | 4.1 | ||
 | Eri | 6ll | 4.5 | 4.3 |  |  | Eri | 696 | 4.2 | 5.1 | |
 | Dor | 1081 | 3.5 | 2.1 |  | Pic | 1446 | 3.9 | 3.7 | ||
 | Vel | 2356 | 2.0 | 1.9 |  | Mus | 3092 | 3.8 | 3.9 | ||
| Car | 2493 | 1.8 | 3.2 | | Pav | 5315 | 3.6 | 2.1 | ||
 | Cen | 3302 | 2.4 | 3.9 | | PsA | 5916 | 1.3 | 4.1 | ||
| TrA | 3879 | 3.1 | 2.2 |  | | Hyi | 458 | 3.0 | 5.0 | |
| Sgr | 4645 | 2.0 | 2.7 | | Car | 1622 | 0.9 | -4.6 | ||
|  | Car | 2503 | 2.2 | -0.7 |  | | Crv | 3172 | 3.2 | 2.3 |
| Boo | 3722 | 3.0 | 4.3 |  | Hyi | 3622 | 5.5 | 4.6 | ||
| Cir | 3739 | 3.4 | 5.0 |  | Cen | 3623 | 2.3 | 6.7 | ||
| TrA | 4030 | 3.0 | 6.2 |  | Lup | 3864 | 3.5 | 4.0 | ||
| Sco | 4457 | 2.0 | -2.6 | | Lib | 3962 | 5.3 | -1.2 | ||
 | | Sco | 4361 | 3.4 | 5.7 | | Apo | 4168 | 3.9 | 4.6 | |
 | Sgr | 4874 | 3.0 | 1.0 | | Sco | 4272 | 2.4 | 6.5 | ||
 | | Vol | 1917 | 4.0 | 0.6 | | Sgr | 4568 | 3.1 | 4.6 | |
| CMi | 2008 | 0.5 | 6.1 | | Sgr | 4628 | 2.8 | 1.3 | ||
 | Pup | 2153 | 2.9 | 2.9 | | Sgr | 4665 | 2.9 | 4.4 | ||
 | Vel | 2324 | 4.1 | 0.0 |  | Sgr | 4809 | 3.6 | 1.4 | ||
 | Oph | 4421 | 4.4 | 5.4 |  | Sgr | 4857 | 3.4 | 5.5 | ||
 | Sco | 4492 | 3.1 | -3.9 | | Ind | 5281 | 3.2 | 2.5 | ||
 | Pav | 4778 | var. | 0.0 |  | Aqr | 5963 | 3.8 | 0.5 | ||
 | | Tuc | 55 | 4.3 | 10.9 | | Gru | 5965 | 4.1 | 4.9 | |
| For | 723 | 4.0 | 8.3 |  | | Cru | 3218 | 3.6 | 5.1 | |
| Lep | 1420 | 3.8 | 9.7,7.1 | | Mus | 3377 | 3.6 | 5.7 | ||
| CMa | 1839 | 2.0 | -4.5 | | TrA | 4250 | 1.9 | -0.6 | ||
 | | Hyi | 74 | 2.9 | 9.7 | | Ara | 4406 | 2.8 | 0.6 | |
| Aur | 1246 | 0.2 | 3.4 | | Tuc | 5747 | 2.9 | 2.6 | ||
| Lep | 1323 | 3.0 | 2.9 |  | | Tau | 1077 | 1.1 | 2.6 | |
| Pup | 2065 | 3.5 | -2.3 | | Pup | 1896 | 2.7 | -2.8 | ||
| Leo | 2618 | 3.1 | 1.5 | | Pup | 1972 | 3.3 | 4.7 | ||
 | Car | 2628 | var. | 1.1 | | Car | 2739 | 3.4 | 1.7 | ||
| Cap | 5507 | 3.9 | (1.1) | | Apo | 3746 | 3.8 | 1.4 | ||
 | | Ret | 994 | 3.4 | 2.6 | | Ara | 4265 | 3.7 | 2.5 | |
 | Vel | 2875 | 2.8 | 2.3 |  | Sco | 4292 | 3.8 | 5.9 | ||
| Hya | 3042 | 3.7 | 5.3 | | Ara | 4304 | 3.1 | 1.5 | ||
| Crv | 3280 | 2.8 | 1.7 |  | | And | 259 | 2.4 | -0.8 | |
| Hya | 3449 | 3.3 | 2.9 | | Hyi | 899 | 3.2 | -1.3 | ||
| CrA | 4871 | 4.2 | 2.0 | | Ori | 1468 | 0.9 | -0.0 | ||
| Pav | 5138 | 3.6 | 9.7 | | Sco | 4193 | 1.2 | -2.5 | ||
| | Phe | 78 | 2.4 | 5.6 |  |  | Eri | 759 | 4.0 | 3.2 |
| Cas | 135 | 2.5 | 1.4 | | Cru | 3263 | 1.6 | 3.8 | ||
| Phe | 245 | 3.4 | 1.6 | | Lib | 3837 | 3.4 | 3.3 | ||
| Phe | 336 | 4.0 | 5.4 | | Her | 4373 | 3.5 | 0.9 | ||
| Ret | 875 | 3.8 | 6.2 | | Sgr | 4617 | 3.2 | 4.9 | ||
| Lep | 1456 | 39 | 8.1 | | Gru | 5854 | 2.2 | 2.8 | ||
| Col | 1459 | 3.2 | 6.2 | |||||||
IV. INTENSITY CHANGES OF LINES WITH UNKNOWN SERIES RELATIONS