[PLASKETT-DELURY| THE SOLAR ROTATION 
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made on each plate. In the 4250 region, two spectra each of the 
latitudes 0°, 30°, 60°, and one at 90° were made on each plate. If any 
of the plates showed a greater displacement in the spectrum at the 
pole than about .03 km., they were rejected on the assumption that 
some instrumental displacement had occurred, and that possibly the 
other latitudes were affected. 
9. The plates of series I and III were measured by Plaskett on 
the Repsold Measuring Engine with an eyepiece micrometer, while 
those of series II were measured by DeLury on the Toepfer Measuring 
Machine with 300 mm. screw. The lines measured in series I and II 
at 45600 and in series III at A4250 are given with intensities, velocity, 
constants, etc., in the following tables. Four settings are made on the 
line in the centre strip and two each on the outside strips, and after 
measurement of all the lines the plate is reversed on the machine and 
remeasured. This diminishes the danger of systematic errors and 
also, as the lines are viewed in the opposite direction in the two cases 
and the number of settings doubled, the accidental errors. 
TABLE I.—Lines 1n 125600 REGION 














| | 
No Wave Ele. | Int. | Velocity ||No.| Wave Ele. | Int. | Velocity 
Length | Constant Length Constant 
1 | 5506-095 | Mn 1 19-336 11 | 5598-524 | Fe 1 18-801 
2 | 5514-563 | Ti 2 | 19-289 12 | 5601-505 | Ca 3 18-788 
3 | 5514-753 | Ti 2 19-287 13 | 5624-769 | Fe 3 18-653 
4 | 5528-641 | Mg 8 | 19-207 14 | 5638-488 | Fe 3 18-575 
5 | 5544-157 | Fe 2 | 19-118 15 | 5658-097 | Y 2 18-461 
6 | 5560-434 | Fe 2 | 19-024 16 | 5682-869 | Na 5 18-320 
7 | 5562-933 | Fe 2 19-010 17 | 5684-710 | Si 3 18-309 
8 | 5578-946 | Ni 1 18-919 18 | 5686-757 | Fe 3 |) 28-297 
9 | 5582-198 | Ca 4 | 18-899 19 | 5688-436 | Na 6 | . 18-288 
10 | 5590-343 | Ca 3 | 18-852 



TABLE II—Lines IN 24250 REGION 










| 
No. Wave Ele. | Int. | Velocity || No. Wave Ele. | Int. | Velocity 
Length Constant Length Constant 
1 | 4196-699 | La 2 26 - 906 9 | 4257-815 | Mn 2 26-400 
2 | 4197-257 | C 2 26 - 902 10 | 4258-477 | Fe 2 26-394 
3 | 4216-136 | C 1 26-745 11 | 4266-081 | Mn 2 26-331 
4 | 4220-509 | Fe 3 26-710 || 12 | 4268-915 | Fe 2 26-296 
5 | 4225.619 | Fe 3 26-666 13 | 4276-836 | Zr 2 26-243 
6 | 4232-887 | Fe 2 26 - 606 14 | 4290-377 | Ti 2 26-133 
7 | 4241-285. | Fe-Zr| 2 | 26-502 15 | 4291-630 | Fe 2 26-122 
8 | 4246-996 | Se 5 | 26-490 || 




