228 Observations upon Auroral and Optical Phenomena. 
still beneath, fainter and of but half the extent. Below this a third 
was just discernible. ‘The successive intervals between the interior of 
the primary and the colored ares were equal,—each being less than 
the breadth of the bow. It appeared to me that all were distinct bows 
lapping upon one another,—the single color above mentioned of the 
supernumeraries was however alone seen, leaving apparently an un- 
occupied interval upon each side of it; probably because the inter- 
vening colors—being some compound of blue—could but feebly 
contrast with the cloud itself. The other colors mingling with the 
superior bows and chiefly with the violet could not be perceived ; 
except in enhancing the dulness of that color, already mentioned. 
Ihave at other times seen a single violet supernumerary arch, 
sometimes exterior and sometimes interior to the primary, but noth- 
ing in the least comparable to the foregoing. I had imagined also 
that [ noticed the same phenomenon in the spray at Niagara Falls. 
So many supernumerary bows as existed in the case mentioned 
by me as being visible at Montreal, form a combination of rare oc- 
currence. The writer of the article “Optics,” in the Library of 
Useful Knowledge, relates the occurrence of the phenomenon to his 
own view with four successive supernumeraries,—the red of each 
lower bow mingling with the violet of the bow next above.* The 
cause of the phenomenon appears yet to be unexplained. 
While on the subject of rainbows, I must not neglect to notice 2 
remarkable attendant upon one of great beauty, which appeared at 
seven o’clock, A. M. on or about Oct. 25, 1836. From the southern 
extremity of this bow, and tangent to it where it met the horizon, 
there arose a vertical column of the same apparent breadth with the 
bow, and having its colors, according to my recollection, in the same 
order. The appearance was faint, but too indisputable to be classed 
as an optical illusion. It did not rise so high as to cut the secondary ; 
indeed, at its upper extremity, it evidently began to have a deviation 
to the right or towards the primary. This shenoninion was witness- 
ed by many persons in different situations, and was a subject of gen- 
eral remark at the meeting of the Conneptiont Academy in the eve- 
ning of the day. 
co, eae 
* Whether the supernumeraries seen by myself were four in number, it 
Sereneyld depend upon the question whether the colored ares were to be 
ed violet or ert Point reapectieg which I had expressed myself ual 
in my minutes 
