1822.] Memoirs of the Astronomical Society, Vol. I. 299 
he not been apprehensive that the giass would have been broken 
by the heat. These experiments were made at about two o’clock 
im the afternoon, in order that they might correspond with the 
time of the eclipse at its greatest obscuration. On the following 
day, about half an hour after the commencement of the eclipse, 
he applied the cloths in succession to the focus of the lens, and 
found the periods at which they respectively took fire to be as 
follow ; viz. © 
Black in twenty seconds. 
Blue in twenty seconds. 
Red in sixteen seconds. 
Yellow in forty seconds. 
At about half an hour before the end of the eclipse, he again 
submitted them to the focus of the lens, and found their periods 
of ignition to be as under; viz. 
Black in seventeen seconds. 
Blue in eighteen seconds. 
Red in fourteen seconds. 
Yellow in twenty-four seconds. 
But during the time of the greatest obscuration, he could not 
produce any effect upon them whatever. The thermometer at 
the commencement of the eclipse was at 66°, and by two o’clock 
had fallen to 612°. This was about the middle of the eclipse ; 
and Mr. Wiseman assures me that at this time he held the bulb 
in the focus of the burning lens for upwards of four minutes, but 
without producing any sensible effect. At a quarter past two, 
he repeated the same experiment, and with the same result, 
although the sun was free from clouds. At the termination of 
the eclipse, the thermometer rose to 64°. Mr. Wiseman also 
states that he fitted up a prism ina darkened room, and that he 
made several observations on the coloured rays which were 
thrown on a screen of white paper. He says, that during the 
continuance of the eclipse, the yellow and blue rays were gene- 
rally increased in brilliancy, whilst the red became exceedingly 
faint, and did not occupy more than half their usual breadth. 
As I am not aware that any experiments of a similar kind were 
made during this eclipse, and as the results are somewhat singu- 
lar, although anticipated by Mr. Wiseman, I have thought it 
right to state them here, in order that the attention of the public 
may be excited thereto in any future eclipse.” Mr. Baily 
received some communications from the Continent, which tend 
to confirm the observations made by former astronomers, on this 
singular and rare phenomenon. ‘The formation of the annulus 
is mentioned by Mr. Albert, at Frankfort on the Maine, by Prof. 
Stark, at Augsburg, who represents its duration to have been 
5% 47/5, by Prof. Schwerd, at Spire, who describes a bright spot 
at the point of one of the horns, six seconds before the annulus 
