THE ORGUEIL METEOR. 359 



done, and possibly with more precision, for other similar meteors. M. Petit, direo- 

 tor of the Toulouse Observatory, proved long ago that these fiery globes describe 

 hyperbolas, a kind of trajectory which goes oif to infinity. Last year on March 4, 

 a meteor which appeared over the north sea, and was observed at different places 

 in England and Belgium, was calculated by M. Heis ; it also had a hyperbolic 

 trajectory, and its initial and terminal heights were 174 and 23 kilometre? with a 

 velocity of 63. Prof. Newton has also executed some similar determinations, and 

 quite recently M. Alex. Herschel communicated to the Royal Society a list of 

 eleven whose orbits were determined. By all these well ascertained cases, we 

 have acquired the certainty that these apparitions are caused by actual asteroids 

 coming from planetary spaces which enter our atmosphere where they describe 

 hyperbolas, and move with velocities comparable to those of the plane's them- 

 selves. 



The question presented more diflSculties in the case of mere shooting stars, but 

 a new instrument came to the help of astronomers — the electric telegraph. M. 

 Heis was the first to make use of it in 1851 between Munster and Herbersthal, 

 Two observers established at these stations examined simultaneously the same , 

 part of the heavens ; when a shooting star, appeared, they announced it by tele- 

 graph, and the signals coincided if it was the same star they both saw. Then 

 they noted carefully its apparent path among the constellations, and this was suf- 

 ficient to enable them afterwards to calculate its trajectory by the method already 

 explained for the meteor of Montauban. Ten years afterwards Father Seechi be- 

 tween Rome and Civita-Vecchia recommenced the same investigation by the 

 same method, which he believed original. A great number of illustrious persons 

 assisted at these investigations, which resulted in proving for the second time, as 

 they had for the first, that the shooting stars are actual meteors, only of inferior 

 dimension, projected in space at a rate of many kilometres per second, and reach- 

 ing our atmosphere to become inflamed. 



It was necessary to enter on these various explanations before considering how 

 the cosmical corpuscles become heated to such a degree as to melt and be dissi- 

 pated. The theory I proceed to describe is the result of successive labors in 

 which many philosophers were concerned. In 1848, Sir J. Herschel in the Edin- 

 burgh Review traced the first outlines of it ; then M. Haidinjer, in 1 861; developed 

 its principle consequences before the Academy of Sciences, but it is only in 1863 

 that M. Reinholds Reichenbach has submitted to rigorous calculation the princi- 

 ples adopted by his predecessors. These investigations allow us to construct 

 theoretically the history of these shooting bodies ; let us see how far it is eonforaa- 

 able to the observed facts.' 



As soon as a meteoric globe with its enormous velocity enters the atmosphere 

 it encounters a resistance which slackens its progress, this resistance being very, 

 great on account of its rapidity ; it can be easily calculated, and, according to M. 

 Reichenbach, it would be sufBeient to destroy almost completely in ten seconds 

 the velocity of a bullet which had been projected at a rate of 100 kilometres per 

 second. Suppose that the meteor bad lost only one hundredth part of its velocity 

 through this cause, there would have been generated a quantity of heat which 

 can be exactly calculated, and which would have been employed in htating the 



