Meteorological and Astronomical Notices. 379 



these appendages. On the present occasion, however, from 

 more attention having been paid to the subject, the state- 

 ments are much more uniform, and observers seem positive 

 to having seen the red prominences occulted by the moon, 

 which they regard as the proof of their being solar pheno- 

 mena, being, in fact, masses of rose-coloured light on the 

 sun*8 surface, upwards of 20,000 miles high. 



It is to be hoped, when all the accounts come to be pub- 

 lished, that something more will be given than merely an 

 ocular impression that a true occultation was eifected ; for it 

 is quite possible to imagine other causes than occultation, 

 which should make the red flames appear to increase in 

 length on one side, and decrease on the other side of the 

 moon. Thus, if they should turn out after all to be spu- 

 rious, that is, some sort of mirage produced by the action of 

 the sun's light grazing on the surface of the moon ; and if 

 the distance to which the red appearance shall extend, de- 

 pends on the intensity of the light, or the distance of the 

 moon's edge from the sun's limb behind it, then we shall evi- 

 dently have a cause which will be altering during the to- 

 tality of the eclipse, and will produce the same effects as the 

 occultation, so far as the mere fact of increase on the one 

 side, and decrease on the other is concerned ; but the quan- 

 tity of that alteration in size, and its law of progression, will 

 be very different to such as is caused by the simple rate of 

 movement by the moon, and therefore may be detected 

 by a series of instrumental measures made during the pro- 

 gress of the totality of the eclipse ; and in this, as many in- 

 stances in the history of science, the choice between the 

 right and the wrong, and widely different conclusions, may 

 all depend on the nicety with which small quantities can be 

 instrumentally measured. 



Visibility of the red prominences under ordinary circum- 

 stances. — While we ought carefully to distinguish between 

 what is actually proved and what is merely indicated, and al- 

 though it has been lately shown in the Edinburgh Observatory 

 to be possible to produce, with peculiar optical experiments, 

 red flames on the sun's limb, of precisely the rose-coloured 

 tint so uniformly described by all the observers, and about 



