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450 Chronicles of Science. | July, 
eye-piece of the telescope divided the centre of the field into nearly 
square spaces, the angular distance between the wires being 56" in a 
vertical direction, and 48” in a horizontal direction. The number of 
particles enclosed at one time within these spaces was estimated to be 
about 300, say about twenty in one direction, and fifteen in the other, 
and scattered equally about. As a deduction from these observations, 
Mr. Dunkin considers that the average length of these particles is 
about 2”, though there are some larger and many smaller. This 
observation was made on March 10th, but on repeating the examina- 
tion on March 16th, the luminous particles appeared more thinly 
scattered, the number estimated to be contained in the nearly square 
spaces being about 200, 
At the April meeting of the Royal Astronomical Society, the 
willow-leaved structure of the sun’s photosphere was again brought 
forward, the Rev. W. R. Dawes affirming that the most recent obser- 
vations had merely landed the different observers where he was six- 
teen years ago. In the beginning of the year 1848 Mr. Dawes, upon 
examining the disc of the sun by means of a transparent diagonal 
on Sir John Herschel’s principle (power 65, aperture 61 in.), observed 
bright particles scattered almost all over the sun, which he then com- 
pared with two excessively minute fragments of porcelain. Four 
years afterwards, assisted by his new solar eye-piece, Mr. Dawes 
arrived at the conviction that these brilliant objects were not distinct 
entities, but were merely different conditions of the surface of the com- 
paratively large luminous clouds themselves—ridges, waves, hills, dis- 
tinguishable brightnesses—parts of the same luminous clouds which 
happen to be brighter than the other parts. These statements gave rise 
to an animated discussion. Mr. Pritchard suggested that Mr. Dawes 
might possibly have been impeded in the correctness of his obser- 
vations, owing to the very minute aperture of his solar eye-piece ; 
diffraction being likely to come into play to an inconvenient extent. 
Mr. Huggins thought that when a high magnifying power was used, the 
rice, or willow-leaved particles lost the uniform appearance which they 
have with a low power. At the same meeting a communication from 
Mr. Nasmyth was read, in which he gives four different forms of 
objects as he observed them. First, he draws the willow-leaves, 
No. 1; No. 2 is shorter, and a little wider; No. 3 is ehorter still, 
and a little wider still; and No. 4 is exactly of the rice-grain pattern. 
No. 1 is the type of those forming the details of the penumbral strata ; 
No, 2 is that which forms the details of bridges; No. 3 is the form 
which constitutes the other parts of the bridges in the margin of the 
photosphere. Both 3 and 4 may be said to be a type of those that 
may be seen over the entire surface of the photosphere. 
Returning from the subject of willow-leaves to the other astro- 
nomical advancements during the past few months, we must not omit 
to mention the list of new double stars discovered by the Rev. W. R. 
Dawes. He gives a list of fifteen, and accompanies them by desig- 
nation, full measurements, and remarks. Some, perhaps most of 
these, are only optically double, yet the example of that highly 
interesting binary couple, ¢ Cygni, may encourage the hope that other 
