291 Solar Observation. 



sity of accumulating other equally excellent series for the future 

 establishment of correct views of this mysterious phenomenon." 

 Amateurs, again, who have not the opportunity, or the inclina- 

 tion to take up the inquiry in a regular and consecutive manner, 

 may yet find it most interesting as an occasional pursuit. No- 

 thing, assuredly, is more grand than the telescopic aspect of 

 that huge incandescent globe ; nothing more marvellous than 

 the dark gulfs which interrupt the continuity of its blaze ; no- 

 thing more surprising than their rapid and almost incessant 

 transformation. These are wonders, indeed, with regard to 

 which, as in the instance of comets, the absence of analogy 

 leads us almost to despair of any adequate explanation; yet 

 this does not detract from the curiosity always attendant upon 

 such gigantic displays of ever-active energy ; and at the pre- 

 sent time the subject receives an addition of interest from the 

 discussion which has been carried on among some of our first 

 observers, as to the exact form and distribution of certain 

 peculiarities in the luminous surface. For many reasons, there- 

 fore, the subject is one with which amateurs may be desirous 

 of becoming practically acquainted. 



The study is, however, not to be entered upon without due 

 caution. There is no other branch of astronomy in which any 

 evil result is to be apprehended for a sight of ordinary 

 strength ; but the sun cannot, of course, be contemplated 

 directly through the telescope without the risk of destruction 

 to the eye ; and even a degree of protection which might be 

 deemed adequate by an inexperienced beginner may prove 

 Insufficient to prevent bad consequences. It has been stated 

 that want of caution in this respect was the origin of Galileo's 

 blindness, and that Sir W. Herschel injured one eye from the 

 same cause. We cannot therefore begin our remarks more 

 appropriately than by giving our readers some hints which may 

 enable them to regard this ocean of flame with safety and 

 comfort. 



Pew pci-sous have such an eagle eye as to be able to fix their 

 sight straight upon the noon-day sun; but there is no reason 

 to think that those who can do bo are sufferers from it, though 

 even iii iln's ease a lengthened gaze might not be desirable. 

 But matters are very different as it regards telescopic vision. 

 In this, there is not only a great concentration of intensity, a 

 large proportion of the rays collected by the object-glass being 

 (loured into the pupilof the eye; but an enlargement of angle, 

 by which the mere luminous point, representing the sun upon 

 the unaided retina, is expanded into a broad glaring disc. The 

 impression of excessive light alono must be expected to bo 

 prejudicial to an organ not originally adapted for such excitc- 

 innt; but that of concentrated heat is probably still more 



