ASTRONOMY AND MKTEOROLOGT. 337 



ren DeLaRue, a few years a<^o, fitted np some apparatus, among 

 the Spanish mountains, to photograph the red appearances, and he 

 was very successful. The photographs proved beyond doubt that 

 the red prominences 'belonged to the sun, and are in no way due 

 to the interposition of the moon, — a point on which there had been 

 previously some doubt. 



This fact having been established the questions arose, "What 

 are these prominences? Are they solid, or are they gaseous?" 

 Further observations with spectroscopes in addition to telescopes 

 and photographic apparatus, would alone be likely to furnish re- 

 plies to the questions, and years had to pass away before another 

 total eclipse of the sun would allow the instruments to be brought 

 to bear upon the phenomena. The foregoing facts explain the 

 intense interest with which astronomers and piiilosophers looked 

 forward to the precious 5 minutes of August last, during which 

 the sun was totally obscured. Many expeditions, fitted out by 

 governments, were in India, watching the eclipse. Among the 

 expeditions in India was one under the superintendence of Major 

 Tennant, which was engaged in photographic work ; another un- 

 der Lieut. Herschel, engaged principally in making observations 

 with the spectroscope ; a third under the charge of Mr. Pogson, 

 astronomer to the Government of Madras; and a fourth, the 

 French expedition, under the management of Dr. Janssen, of 

 Paris. All these observers took up positions in the eastern part 

 of India, principally in the neighborhood of Guntoor and Masuli- 

 patam. Mr. Pogson intended to observe either at Masulipatam 

 or Narsipore ; he also stationed one assistant at Gunnapoor, and 

 another near to Beejapore, towards the Bombay side. 



Major Tennant and his party of sappers, took out with them, to 

 photograph the eclipse, a great telescope, which was constructed 

 by Mr. John Browning. This telescope has a mirror of silvered 

 glass, 9| inches in diameter, and 5 feet 9 inches in focus, throwing 

 a picture of the sun a little more than three-quarters of an inch in 

 diameter, from the circumference of which the red flames and 

 other phenomena would radiate. Consequently, the plates of 

 glass to receive the picture were about 4 inches square. The im- 

 age of the sun was not thrown directly upon the photographic 

 plates by the mirror, but a small plane mirror was interposed to 

 throw out the image at the side of the tube, as in the Newtonian 

 telescope. 



The spectroscopic observations in India were very successful, 

 and all the observers agreed that the protuberances are gaseous in 

 their nature. 



The last fact has an importance of its own. The cause of the 

 heat of the sun has long been a puzzle to philosophers. The heat 

 is not produced by common combustion, for a rough approximation 

 to the real quantity of heat given off continuously by the sun has 

 been ascertained by experiment and calculation. It is also known 

 that if the sun were a globe of coal continuously supplied with 

 oxygen, it would all be burnt out in about 5,000 years. There is 

 also evidence that the sun is not a hot body now cooling. 



Phinetarv dust and small stones al)ound within the limits of the 



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