(601) 
details of the polar streamers. Nrs, 8 and 9 however are entirely 
spoiled by clouds and by direct sunlight. 
The plates 4, 5 and 6 were fitted with rotating aluminium screens 
(BURCKHALTER apparatus) with a view to obtaining faint and bright 
parts of the corona on the same plate. Three screens of different 
shapes had been selected. In consequence of the cloudiness, it has 
unfortunately not been possible to bring the moon exactly on the centre 
of the plate, and to keep it there, so that the axis of rotation of 
the screens did not coincide with the centre of the moon’s image. 
Nt. 4 on one side shows details of the structure of the corona; 
Nr. 6 shows the corona to a distance of 20’, Nr. 5 to 15’ from the 
moon’s limb; the rotating screen of this plate evidently was too 
small, so that the corona-streamers are lost in the completely fogged 
outer parts of the plate. 
III. ,,40-feet” coronagraph (f = 11.77 m. = 91a). 
This lens was most kindly lent us by the Superintendent of the 
U. S. Naval Observatory, Washington D. C, to whom we tender 
most cordial thanks. 
The original size of the plates was 50 x 60. Having satisfied 
ourselves that no parts of the corona, nor any stars would be lost by 
the proceeding, we cut them down to 24 X 30 in order to ensure 
a safer transport. During this operation nr. 2 was broken into three 
pieces, without spoiling, however, the essential parts of the image. 
On Nr. 1 (2/3 sec. Lumière bleue) accidently three exposures of 
different durations have been impressed; some of the prominences 
have consequently gained in details, while others are smudged together 
and unfit for measurement. 
Nr. 2 (20 sec. Lumière jaune) shows very fine prominences and 
complicated details of the inner corona, which forms dome-shaped 
ares round the prominences. 
Nr. 3 (40 sec. Lumiere bleue) is nearly as good as the former. 
Nr. 4 (180 sec. Lumière bleue). This plate was fitted with a 
large rotating screen. According to the programme a short time 
before the beginning of totality the mirror of the coelostat should 
be definitively adjusted so as to throw the image of the sun exactly 
on the centre of the plate. Notwithstanding the aperture was 
greatly reduced, the sunlight was still so strong that Mr. MuLLeRr, 
fearing a fogging of the freely exposed plates, dared not admit the 
sunlight for more than a single moment. The image of the sun appar- 
ently has fallen much too high on the plate, so that the centre 
