2 532 
a Number of lines. | 5 5 
| 
| | 
3650—4450 | | A} f 
I 287 | 0.0050 A 0.0081 A 
mean 4050 
4450—5250 | | 
Il. | | 118 | 0.0042 0.0097 
mean 4850 | | 
52506050 | 
Ill. 41 0.0065 0.0113 
mean 5650 | 
The foregoing should give the answer to the question whether the 
existence of a gravitational displacement as required by the general 
relativity theory is compatible with the observations. The numerical 
values deduced from that theory are indicated by d' in the table 
and by the double line G in the diagram. 
The ordinates of G refer to displacements of the cores of the 
solar lines with respect to the terrestrial lines. Taking into account 
that the observed Fraunhofer lines are dispersion lines, and, therefore, 
are generally displaced towards the red with respect to their cores, 
we see that, if the Eistum effect did exist, the total displacements 
of the Fraunhofer lines with respect to the terrestrial lines would 
group themselves around mean values ranging from 0,008 + 0,004 = 
0,012 A at 2 4000 to 0,012 + 0,006 = 0,018 A at 2 6000 (as shown 
by the broken line at the top of the diagram). 
These theoretical mean values average 0,010 A higher than those 
actually observed — a difference far too great to be attributed to 
accidental errors. 
It is of course possible — although not probable — that there 
exists an as yet entirely unknown cause of general displacement of 
Fraunhofer lines towards the violet, exactly balancing the gravitational 
displacement. One should also keep in mind the possibility that the 
are lines have failed as yet to make the terrestrial frequencies 
known with sufficient precision, and may prove to be systematically 
displaced towards the red by so much as 0,010 A. 
On the basis of our present knowledge, however, we are forced 
to conclude that the gravitational displacement does not exist. 
We feel greatly obliged to Dr. M. Minnarrt and Miss C. B. BLEEKER 
for their active collaboration in analyzing the data at our disposal. 
Utrecht, May 1920. Heliophysical Observatory. 
