1889. | NEW YORK ACADEMY OF SCIENCES. 155 
scopes and cameras ; a 5-inch telescope was used for a study of 
the brightness of the inner corona and the protuberances ; the 
8-inch Boyden telescope on the outer corona; and with the 13- 
inch Boyden photographic telescope, the largest ever used in an 
eclipse, 8 plates were taken, with varying exposures, to show 
every part of the corona in its proper relation. These negatives 
show the moon 1% inches in diameter. With the 8-inch Bache 
telescope were taken 6 negatives to show the outer corona and 
possible intra-mercurian planets. 
With the 40-foot photoheliograph at the Lick Observatory, 
where the eclipse was not quite total, twelve views of the partial 
eclipse were taken between clouds. 
(4) Spectroscopes. 
In the main, the spectroscopic work was done by the Harvard 
party, and was wholly photographic. Hight spectroscopes were 
used. The new reversing-layer spectroscope, specially devised 
for this eclipse, was brought into service 10 seconds before, and 
continued till 30 seconds after, totality. Also a quadruplex 
spectroscope was used to give spectra of different tracts of the 
corona simultaneously. Plates stained with erythrosin carried 
the spectrum low down in the red, while quartz lenses and prisms 
were used for the ultra-violet. Of the preliminary spectroscopic 
results Mr. Pickering writes: ‘‘ Three good spectra were secured, 
showing all the lines present between F and L. If there were 
any other lines present in that region, they must have presented 
so little contrast to the background of continuous spectrum that 
the present photographic plates would be unable to show them. 
The spectrum was very simple, however, showing only 4 or 5 
lines besides those of hydrogen. Solar spectra were taken prior 
to the eclipse, which will enable us to identify the position of 
all the lines. I have one curious spectrum taken on an erythro- 
sin plate, with a line which I have not as yet identified, but 
which I think will probably show the 1,474 line.” 
Mr. Barnard employed a common form of prismatic camera 
for the coronal rings and protuberances, and Mr. Keeler, also of 
the Lick Observatory party, repeated Hastings’ observation with 
the double prism. Mr. Keeler’s preliminary conclusions are 
that ‘‘a coronal spectrum-line cannot always be an index of the 
height to which the corresponding gas extends in the corona 
itself; and that the behavior of the 1,474 line (and others) at the 
two limbs of the sun does not seem to justify the belief that the 
corona is chiefly, or in any great degree, a diffraction pheno- 
menon.” 
