ASTRONOMICAL PHENOMENA AND PROGRESS. 



43 



In a recent essay, M. Chacornan expresses 



the opinion Unit the .sun is a liquid inrando-ivnt 



MUTounilL-d by a dense and imperfectly 



atmosphere. In this atmosphere 



; ir vapors, raised by evaporation from 



tli. liquid nucleus, ascend till acted upon by the 



-tial spaces, when they are con- 



! into luminous crystals. He attributes 



jpota to the engulfment of vast areas of 



photospherio crystals, which lose their 



brightness as they sink. Another observer 



s of "several roundish, isolated portions 



f luminous matters (having the appearance of 



LTS floating in a black sea) in the centre 



of an umbra." 



During the year ending August 1, 1866, 282 

 ives of the sun were taken in 158 days by 

 tin; hdiograph at Kew. The areas of the spots 

 and penumbra were accurately measured, and 

 the heliometrio latitude and longitude calcu- 

 lated. 



Father Secchi has completed the reduction 

 of magnetic observations made during the years 

 1859-'C5, and of sun-spots during the same 

 period. The results show the reciprocal in- 

 fluence of periodic variations of spots and of 

 amplitudes of the daily magnetic oscillations : 



It will be observed that the minimum of 

 spots corresponds to the minimum of magnetic 

 variations. 



Spectra of some of the Fixed Stars, the Moon, 

 and Planets. Messrs. Huggins and Miller have 

 spent much time during the past two and a 

 quarter years studying the spectra of the fixed 

 stars. Very few nights were favorable for ob- 

 servations, owing to the ever-changing want 

 of homogeneity in the earth's atmosphere. The 

 light of bright stars is very feeble when sub- 

 jected to the large dispersion necessary to 

 give certainty and value to the comparison of 

 the dark lines of stellar spectra with the bright 

 lines of terrestrial matter. For the purpose of 

 these examinations, Messrs. Huggins and Miller 

 made great improvements in the apparatus 

 employed, bringing it to a point of perfection 

 hitherto unknown. About fifty stars were ex- 

 amined by them, but their principal etl'orts 

 were concentrated upon three or four of the 

 brightest, the spectra of which are as rich in 

 .iiu-s as the sun. The few really fine nights 

 which arc available whilst a star is well situated 

 for such observations in respect of altitude and 



sun-setting, make the complete investigation 

 of a star the work of some years. 



Aldebaran (a Tauri) a pale-red star is 

 strong in the orange, red, and green lines. Nine 

 of its spectra are coincident with certain lines 

 in the sun-spectrum, indicating the presence of 

 sodium, magnesium, hydrogen, calcium, iron, 

 bismuth, tellurium, antimony, mercury. No 

 coincidence was observed with nitrogen, co- 

 balt, tin, lead, cadmium, lithium, and barium. 



a Orionis (Betelgeux) an orange-tinted 

 star shows strong groups of lines, especially 

 red, green, and blue. The lines are coincident 

 with those of sodium, magnesium, calcium, 

 iron, and bismuth. 



ft Pegasi of a fine yellow color reveals 

 the presence of sodium, magnesium, and per- 

 haps barium. The absence of hydrogen lines 

 in this star and also a Orionis, is an observation 

 of considerable interest. 



The spectrum of the brilliant white star 

 Siriug is intense, but owing to its low altitude, 

 the observation of the finer lines was rendered 

 difficult by motions of the earth's atmosphere. 

 Sodium, magnesium, hydrogen, and probably 

 iron lines, were found. The hydrogen lines 

 were strong. The white star, a Lyra?, strongly 

 resembles Sirius through the spectroscope. The 

 spectra of Capella, a white star, and Arcturus 

 (red), are analogous to the sun. In the last- 

 named star the sodium line was ascertained 

 beyond a doubt. In Pollux, coincidences were 

 remarked with the sodium, magnesium, and 

 probably the iron lines. Sodium lines are dis- 

 covered in a Cygni and Procyon. 



In the moon, no other strong lines are visi- 

 ble than those of the solar spectrum, when the 

 sun has a considerable altitude. The quantity 

 of light from different parts of the moon is 

 very different, but the lines of the spectrum are 

 in every case the same. The result of these ex- 

 aminations is wholly negative as to the exist- 

 ence of any lunar atmosphere. 



Lines of orange and red are discovered in the 

 spectrum of Jupiter, which are attributed to 

 the modification of solar light before reach- 

 ing our atmosphere, and are therefore due 

 probably to absorption by the atmosphere of 

 Jupiter. On one night, the moon and Jupiter 

 being near each other, the opportunity was 

 seized to compare them directly with each 

 other, and these lines were the only percepti- 

 ble difference observed between the two bodies. 

 Similar bands in the orange and red are seen in 

 Saturn. 



In Mars no lines were detected in the red, 

 like those in Jupiter and Saturn, with the ex- 

 ception of two or three strong lines in the ex- 

 treme red. The spectrum of Venus is of great 

 beauty, corresponding with that of the sun. 



Comets. Comet 1, 1866, was an oval nebu- 

 lous mass, surrounding a very minute and not 

 very bright nucleus, which possessed no sen- 

 sible magnitude in the telescope. The light 

 of the coma was different from that of the 

 minute nucleus. The latter was self-luminous, 



