
RED PROMINENCES SEEN DURING TOTAL ECLIPSES OF THE SUN. 447 
In reference to this opinion, Mr Arry has observed, “that in the rapid passage 
of the moon’s shadow he conceived it impossible to find air in the state required 
for the explanation”* proposed by M. Fayr. But even if the atmosphere 
exist in the state he has supposed, it is evident that the inequality of tempera- 
ture in the successive layers of air, must decrease rapidly from the surface of 
the shadow inwards, and hence the phenomena of mirage must vary, according 
as the observer is situated near the edge of the shadow or near its centre. If 
then, the prominences are caused by the unequal heating of the air, on the two 
sides of the path of light ; we might expect them to attain their maximum size 
and distinctness near the beginning and end of the total phase of the eclipse, 
and about those times, they ought to vary rapidly in appearance: for the light 
passing near the surface of the shadow then traverses, in succession, strata of 
air of rapidly decreasing temperature. Near the middle of the totality, on the 
contrary, the phenomenon ought to be almost insensible, as the rays then traverse 
air far removed from the heating action of the sun, and of nearly uniform tem- 
perature. Let us inquire how this agrees with what was actually observed 
at the late eclipse. 
Mr Dunx:n remarks, that one of the prominences “ was most curiously formed, 
having something of a horned shape;” that his “eye was intently fixed upon it 
for about a minute of time, and during that interval not the slightest change took 
place in its form.”+ Lieutenant Perrersson “observed no change [in the form 
of the prominences] that was not due to the motion of the moon.” { According to 
Mr Avie, “no change was observed in the form or position of the prominences, or 
in the position of the detached mass of light [relatively] to that of the crescent, 
farther than that due to the motion of the moon; nor did there appear any insta- 
bility or wavering, in their colour or intensity.”) Mr CarrineTon “ cannot 
depose to have seen the slightest change’’ of outline in the large prominence: and 
he afterwards states, that the prominences had “ hard and well-defined outlines.”’|| 
Mr LasseEtu states, that “ the prominences were of a most brilliant lake colour, a 
splendid pink, quite defined and hard. They appeared to him ‘ not quite quiescent, 
but the moon by her movement might cause an idea of motion.’”4{ With refer- 
ence to the largest prominence, Mr Hinp says he “ perceived no change of form 
or motion, and it was visible four seconds after the sun reappeared, but detached 
from the sun, the strong white light of the corona being visible between it and 
the sun.”** Mr Dawes observes, regarding the same prominence, that “its apex 
was paler than the base, and of a purplish tinge; and it certainly had a flicker- 
* Lecture by Mr Airy on the Total Solar Eclipse of 1851, July 28, p. 6.—Athenewm, No. 
1230, p. 559. 
+ Ast. Soc. Notice, p. 46. t Ibid., p. 58. § Edin. New Phil, Journal, 1851, p. 375. 
|| An Account of the late Total Eclipse of the Sun, by R. C. Carrinaton, Esq., pp. 7, 10. 
4 Ast. Soc. Notice, p. 53. ** Thid., p. 67. 
