The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1870-03-26 00:00:00

MR. LOCKYER ON THE SUN.

In London, on Saturday afternoon, the first of a
cotlrse of four lectures by :NI r. J. Norman Lockyer,
F.R.S.' on "The Sun," was delivered in the Theatre
of the Royal Institution. JULIE. Prince Christian
oecupied the chair, and among the company were the
Queen of Holland. the Bishop of Winchester, Lord
S. raquril de Redcliffe, Lord Houghton, Sir IL Holland,
Sir W. Sarling, Sir E. Pearson, Sir J. Rowe, Dr.
GI,. Istone, Professor Tyndall, &c. _

After a few brief observations on the astronomy of the
ancients and the place of the sun in ancient systems, Mr.
Lockyer observed that in nicilern times the study of the
ow hail resulted in very Important discoveries ; Bonin of
thesis had been printed by the sun itself through the
medium of photography, an that a ith regard to them
there could not be any mistake. A study of the general
surface of the sun had led to various suggestions being
made to account for the spots upon its surface, and
other phenomena seen only during a total eclipse. In
noting these phenomena it was necessary to distinguish
the photosphere—the light portion of the sun, the pe-
numbra, or shaded part, and the umbra, or darker portion,
and lastly, that into which the umbra receded and which
was comple•ely obscured, A partial eclipse of the son did
not reveal these differences; but in a total eclipse they were
very interesting phenomena At the last total eclipse accu-
rate observations were made, and these Mr. Lockyer exhi-
bited by means of the electric light. From the outer edge
of the sun there proceeded enorninani rays of golden and rosy
light, and red flames appeared to barn between them on the
sun's surface. The observation of the red tame was that
made in 1706 ; but time out of mind the corona had been
visible and dwelt upon by different ostronomers. But their
means for taking accurate observations were incomplete: they
were, indeed, confined to observing the sun's motion, end
his place in the universe but having only one observatory,
that at Alexandria, they could not determine with any
accuracy even the sun's place. In 1540, Tycho Brahe,
the Dane, completed his observatory, and made dining his
life many discoveries; but the telescopes which he and
Galileo used were very small •, and they never thought of
interposing a piece of coloured glass between their eye and
the sun, so that their olpervations were confined to early morn-
ing and evening. Modern observers, however, had the ad-
vantage of impr,ved instruments, and above all of the
spectroscope. By the aid of electric light Mr. Lockyer ex-
hibited on the screen spectra of sodium, magnesium, and
iron, pointing out how, by epectrmin analysis, the consti-
tuent elements of the sun might he ascertained. In con-
nection with this Mr. Mayer advanced an Interesting
theory an the result of experiments made by himself and
Dr. Banklin with regard to the variations of the spectrum.
These experiments had led him to believe that these varia-
tions soi e not attributable, as hail hitherto been thought, to
the state of our atmosphere, but to pressure—the inference
being that the spectrum analysis would not only reveal the
composition of the sun, but the pressure existing on its sur-
face. Mr. Lockyer showed experimentally how pressure
could be produced to cause changes in the spectrum.