is, however, most probably too high, as will be inferred later from the ionization temperature scale.
For the cooler stars small discrepancies also occur among the different observers. In the writer’s opinion, the lowest estimates for the temperatures of the cooler stars are probably nearest to the truth.
[TABLE VI]
| Star | Abott Radiometric | Coblentz Thermoelectric | Plaskett Wedge Method | Sampson Photoelectric | |
|---|---|---|---|---|---|
 | Ori( ) | 13000° | 25000° | ||
 | Cas( ) | 15000° | 30000 | ||
| Per() | 15000 | 14000 | ||
 | Ori( ) | 16000° | 10000 | 14800 | |
 | Lyr( ) | 14000 | 8000 | 11600 | |
|  () | 11000 | 12800 | ||
| ( | Cyg( ) | 9000 | 9000 | 10900 | |
| Aql( ) | 8000 | |||
 | Cas() | 9000 | 10700 | ||
|  ( ) | 6000 | 8300 | ||
| Aur( ) | 5800 | 6000 | 5500-6000 | 5500 [*] |
|  ( ) | 4000 | 4200 | ||
| Gem() | 5500 | 5000-5500 | 4200 | |
| Tau( ) | 3000 | 3500 | 3400 | |
| Ori( ) | 2600 | 3000 | 3400 | |
| Peg( ) | 2850 | 3200 | ||
[*] Temperature assumed in calibration of scale.
It was mentioned at the outset that dwarf stars appear to be at a higher temperature than giants of the same spectral class. The following table summarizes the differences in temperature, as compiled by Seares.[56]
[TABLE VII]
| Class | Effective Temperature | |
|---|---|---|
| Giant | Dwarf | |
| 6080° | 6080° |
| 5300 | 5770 |
 | 4610 | 5500 |
| 3860 | 4880 |
| 3270 | 4120 |
| 3080 | 3330 |
A more detailed list of giant and dwarf temperatures was compiled in 1922 by Hertzsprung[57] from all the material then available. The tabulation that follows contains his values for