288 PROFESSOR PIAZZI SMYTH ON 
on the mind of him who was privileged through so many weeks to contemplate 
the scientific glory and mysterious physical complexity of the light of an almost 
Zenith Sun, with a degree of instrumental power not yet possessed by many 
persons in the world. 
This feature was, the absolutely greater number of lines on approaching the - 
violet end of the spectrum. Beginning at the opposite or red end, there were 
often there large spaces without any lines at all. Spaces where you seemed to 
be looking into unfathomable ocean depths of nothing but pure, elemental scarlet 
light ; and not even the thinnest spider’s thread of a line was floating on their 
surface anywhere. But in further advance along the spectrum, first in the 
citron, and then in the green, the lines were evidently more numerous and often 
thicker ; and in the glaucous region more abundant still. While after passing 
F, a new feature began to appear; for amongst the other and stronger lines, 
faint visions of graduated bands and groups of markings from the extreme 
distance almost floated into view like ghosts, and became at length so numerous 
as almost to dispute standing room with one another. 
Continually too, with every further advance towards the violet, these 
eraduated bands of close fine lines became more and more pronounced, occa- 
sionally including some decidedly strong lines ; while amongst them again were 
not unfrequent specimens of perfectly gigantic size; and this too although I 
was continually decreasing the dispersive power of the spectroscope (after 
having passed the spectrum’s most luminous portion), to half, or a third, or even 
a fourth only of what it was before.* 
Now there are many very thick lines in that other grand Solar Spectrum 
Map of the world in the present age, viz., Professor KircHorr’s ; but somehow, 
I was never much impressed with their being a great deal more than a mere 
stretching out by a new hand, not Kircnorr’s own, of the exaggerated length of 
the violet in all uncorrected prism representations. But here, in these observa- 
tions in Portugal, what with the heat of the atmosphere, and the blinding 
light outside the house, and the magnificent action of the prisms with large aper- 
tures and powerful dispersions, causing one to travel slowly, and most carefully, 
making micrometer observations all the time, over immense angular distances, 
from one resplendent colour region of inimitable purity and ravishing beauty to 
another, there was first of all a reality of impression conveyed, respecting the 
awful supernal temperatures of those celestial fires ; fires containing not only so 
much red and yellow, but such sublime blue and surpassing violet radiations ; 
plunged into whose higher degrees, therefore, anything earthly would be utterly 
dissipated and vanish ; and then it was exactly in the very culminating regions 
* This was in fact adapting each part to our Wave-number Scale ; for, without such reduction, a 
prism formed spectrum is nearly sixteen times longer in the violet, than it is in the red, region, as 
compared with a diffraction spectrum, 
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