75 
Meudon, of copies of some of liis very beautiful photographs 
of the sun’s surface, caused me to refer to a paper commu- 
nicated to this society by Mr. Nasmyth, in March, 1861. 
This paper appears to have been the means of directing the 
attention of astronomers to the structure of the surface of 
the sun. The appearances referred to do not relate to the 
spots or faculee, but generally to the mottled character of 
the solar surface. It was, however, in the neighbourhood 
of a large spot that Nasmyth pictured the “willow-leaves,” 
so as to show the distinct character of the markings, although 
he could see the characteristic forms away from spots. It is 
not denied that other observers had noticed peculiarities, 
but the term mottled appears to have been considered 
sufficient to describe what was seen, but it was not until 
Mr. Nasmyth published his drawings that special notice 
was given to the matter. The subject was soon warmly 
discussed amongst astronomers, and the publication of Mr. 
Nasmyth’s paper led to the production of many drawings, 
each observer having his ov/n idea of the term suitable to 
describe the appearances seen. One of the keenest and 
most careful observers, the late Rev. W. R. Dawes, thought 
the objects “ much like a piece of coarse thatching with 
straw, the edges of which had been left untrimmed.” Mr. 
Stone, at the Greenwich Observatory, called the objects 
“ rice-grains.” Secchi, at Rome, in 1869, described them as 
“ leaves.” “ The leaves,” he says, “ in the neighbourhood 
of the spot were oval, the greater diameter about three 
times the less,” and he asks, “ What are these things ? 
They are veils of the most intricate structure.” It will be 
noticed that Secchi’s description agrees very well with 
Nasmyth’s. Dr. Huggins differs from the other observers, 
and calls the luminous objects “granules” (an old term — 
Herschel calls them “nodules”), and does not think that 
they interlace as Nasmyth supposed. The American astrO“ 
nomers were not idle during this discussion. One of the 
most beautiful drawings yet produced is by Mr. S. P, 
