105 



will grow to I cannot tell. But I never forget my birth-place, 

 and you, as a native like myself, will never forget that you are 

 a citizen of no mean city." 



In the discussion which followed, many additional interesting 

 particulars of Old Burnley, were brought out by Mr. Joshua 

 Eawlinson and others. 



SOLAR FLAMES. 



By Rev. A. L. CORTIE, S.J., December 13th, 1887. 



History and Methods of Observation. 



The appearance of the sun, as viewed by the naked eye, is that 

 of a round white disc, the apparent diameter of which, when the 

 glare caused by our atmosphere has been removed, subtends an 

 angle of little more than half a degree, or about the same angle 

 as a penny piece would subtend when seen at a distance of 

 seventeen feet. The surface of the sun visible to the naked 

 eye has received the name of the photosphere. If we project 

 its image by means of even a small telescope upon a screen we 

 see that this visible disc is by no means of a uniform whiteness. 

 In the first place there is a darkening at the limbs, due to the 

 solar atmosphere, and moreover the whole surface is made up 

 of a net-work of dark and white patches, giving to it a peculiar 

 mottled or granulated appearance. Here and there we shall 

 probably distinguish dark dots called pores, and perhaps a 

 sun-spot, with its dark interior or umbra, surrounded by a veil 

 of a tint not so black, and called the penumbra. This penumbra 

 is furrowed by bright streaks, all radiating towards a still 

 brighter ring, which forms the boundary between it and the 

 umbra. Again, we are likely to see brUliant white patches of 

 irregular shape called faculae. These are more easily dis- 

 tinguishable at the hmb, where they stand out by contrast with 

 the darker background. They are usually of filamentous or 

 streaky form. They invariably follow an outburst of spots. 



Surrounding the photosphere are the wonderful forms of the 

 sun's atmosphere, which no telescope will show us, and which 

 are only rendered visible when the moon places herself between 

 the sun and earth, or when, by means to be explained later, 

 they are seen in the spectroscope. For present purposes we 

 may distinguish two parts of the solar atmosphere. First, a 

 rose-coloured stratum of glowing hydrogen, some three thousand 

 six hundred miles in depth * out of which rise the flames called 



* The mean height of the chromosphere, as derived from the six years' observa- 

 tion, 1880-85, made at Stonyhurst, is 8""07. The linear value of 1" on the smi'a 

 surface is very nearly 450 miles. Hence the mean height in miles of the chiomo- 

 sphere becomes nearly 3630 miles. 



