Birmingham age-herald., 1895-02-08
A STUDY OF THE SUN.
A FASCINATING RECREATION WHICH
 ANY ONE MAY ENJOY.

How It May Be Observed Without Danger.
 A Method of Getting Perfectly Pure
 Beam For Inspcction-A Lesson Tn As-
 tronomy C1uched In Simple Terms.
 Every day royal presence, attended by numerous unseen courtiers, sweeps across tho sky. The sun looks us so boldly in the face that we are compelled to veil ourselves from his acc1rsing gaze. Let us commence our new studies by contemplating his at- tractiyeness.
 A piece of we'll smoked glass will give us good service. If this be covered with another piece, with strips of paper at the edges to separate them and prevent rub ping, and other mucilaged strips to bind the outer edges, we shall have a respecta- ble and lasting astronomical instrument.
 The eye may now examine the dazzling orb without danger, and 10 will discover disk which is apparently no larger than that of the full moon, but tho fact that the sun is about 400 times farther away accounts for the resemblance in size But tho disk is not all of the immense world, for a very important envelope of vast di- mensions is invisible except to special in struments. Tho limb of tho sun is seen to be not quite so bright as tho central DOT tions, because the light from 1t has to penetrate a greater depth of atmosphere.
 Occasionally we sec "spot" upon the solar surface, in which case it must be very large, but if we are fortunate enough to havc access to even small spyglass we shall many times see spots There arc years when the spots arc very numerous (the writer counted 168 one day and moro than 800 on a day in 1S93), and years when none Is seen for months, and this appears to be governed by ''period'' of about II years.
 If we use telescope with our smoked glass, the spectacle will be curiously in- teresting, for the object glass-a very large eye-gathers many rays of light and bends them to focus, producing magnificd image which is yet more enlarged by the eyepiece which is a microscope. Now, the very grain of tho sun, so to speak, is visible, the surface being completely flecked with gray white matter, while here and therehuge masses of white protrude. These latter arc called facul@ and arc usually associated with tho spots which arc de- pressions in the surface-deep, dark cavi- ties, but dark only as entrusted with tho shining regions, for they arc brighter than the calcium light Very recently the writ CT measured large group and found that it occupied an area of more than 100, 900 miles in length and about three fourths as wide into which could be cast 100 earths without crowdiDg them. Still larger groups have sometimes been noticed. Watching the spots from day to day re- veals the time of revolution of the sun upon its axis, about 25 days which means that one day on the sun is as long as 25 of ours.
 As yet the sun has not yielded the secret of its composition, and the telescope, un- aided, is inadequate to solve the mystery. Perhaps in childhood we bcguiled hours of church service, which were trif1e wearisome to little ones, by noticing the play of color in the ''lusters' which hung in profusion from the old fashioned lamps. How little we dreamed that the sun was whispering through this simple medium intelligible messages of very high impor- tance, for this three faced form of glass is called a prism, tho change of direction of objects viewed through it being due to tho bending (refraotion) of tho rays of light passing through it, and the color fringe along tho edges of the images the primary rays of which white light is composed, which is easily proved by passing the col ored rays through another prism, when
 
 more
 The same color band, or spectrum is shown by a grating of parallel wires strung in frame, or by close grained feather, or even by the eyelashes when the eye is half closed.
 But we can easily improve upon these primitive instruments by employing a series of prisms of fine construction or Q grating produced by ruling lines with diamond upon piece of perfectly flat and highly polished speculum metal.
 To get perfectly pure beam for inspec- tion we let tho telescopio image of the sun fall upon delicate slit in metal plate, which is in the focus of tho object glass of little telescope, whose duty 1t is to make parallel the rays to be examined, and which sends them through the series of prisms referred to or causes them to fall upon 0 grating. In either case they are viewed by another littlo telescope, and the beam of sunlight tells it's story in mag nificent spectrum, far exceeding the rarest touches of world renowned artists.
 Now for the precious secret! The beau tiful color band is threaded with thousands of slondor dark lines, which correspond with the bright lines, which are the sign manual of metals in glowing state, and We Hceu ohly to put plncn or salU III bne 1amo of a candle and let tho light fall alongside the suns image on the slit. when there will be two spectra, side by side, and the two bright yellow lines of sodium will exactly coincide with two black lines in the orange of the solar spec- trum, and the crowning proof appears when the calcium light is permitted to shine through tho candle flame, instantly turning the bright lines to dark ones. So with the lines of other metals. We have learned from the suns own messages, aft CT n journey of 93, 900, 900 miles, that it is gaseous body; that many of the metals of earth are vaporized in its awful tenn perature, and that the surface is probably shell of luminous clouds surrounded by an atmosphere" of gases thousands of miles deep, out of which spurt for hun dreds of thousands of miles, with speed in contrast with which the movement of whirlwinds on earth is dead calm, jets ofs flaming hydrogen intermingled with the metallic yapors, which, becoming cooled by exposure to the cold of space, fall upon the surface and cause the d.pressions known as spots. Ledger.