rful magnetic impulses may be projected upon us at the
moments when such streamers are pointing towards the earth.

Some interesting investigations with regard to sunspots have recently
been published by Mrs. E.W. Maunder. In an able paper, communicated to
the Royal Astronomical Society on May 10, 1907, she reviews the
Greenwich Observatory statistics dealing with the number and extent of
the spots which have appeared during the period from 1889 to 1901--a
whole sunspot cycle. From a detailed study of the dates in question, she
finds that the number of those spots which are formed on the side of the
sun turned away from us, and die out upon the side turned towards us, is
much greater than the number of those which are formed on the side
turned towards us and die out upon the side turned away. It used, for
instance, to be considered that the influence of a planet might
_produce_ sunspots; but these investigations make it look rather as if
some influence on the part of the earth tends, on the contrary, to
_extinguish_ them. Mrs. Maunder, so far, prefers to call the influence
thus traced an _apparent_ influence only, for, as she very fairly points
out, it seems difficult to attribute a real influence in this matter to
the earth, which is so small a thing in comparison not only with the
sun, but even with many individual spots.

The above investigation was to a certain degree anticipated by Mr. Henry
Corder in 1895; but Mrs. Maunder's researches cover a much longer
period, and the conclusions deduced are of a wider and more defined
nature.

With regard to its chemical composition, the spectroscope shows us that
thirty-nine of the elements which are found upon our earth are also to
be found in the sun. Of these the best known are hydrogen, oxygen,
helium, carbon, calcium, aluminium, iron, copper, zinc, silver, tin, and
lead. Some elements of the metallic order have, however, not been found
there, as, for instance, gold and mercury; while a few of the other
class of element, such as nitrogen, chlorine, and sulphur, are also
absent. It must not, indeed, be concluded that the elements apparently
missing do not exist at all in the solar body. Gold and mercury have, in
consequence of their great atomic weight, perhaps sunk away into the
centre. Again, the fact that we cannot find traces of certain other
elements, is no real proof of their entire absence. Some of them may,
for instance, be resolved into even simpler forms, under