A. MATHEMATICS AND ASTRONOMY. 1 9 



lately been studying the zodiacal light under the very favor- 

 able sky of Rio Janeiro, and comes to a different conclusion. 

 He finds that this does not differ from ordinary sunlight, but 

 gives a continuous spectrum. It is, however, too faint to see 

 any dark lines. This result is confirmed by Rev. T.W.Webb, 

 of England, who has recently been observing the zodiacal 

 light with a spectroscope which shows the auroral line very 

 distinctly. He sees nothing like the green auroral line in the 

 zodiacal spectrum. 



SCHIAPARELLI ON THE NATURE OF METEORS. 



The gold medal of the Royal Astronomical Society of Lon- 

 don has recently been presented to Signor Schiaparelli for 

 his remarkable discoveries in meteoric astronomy. His study 

 of this subject received a great impulse from his observations 

 of the meteors which fell on the nights of August 9, 10, and 

 11, 1866, and he was then confirmed in the opinion, expressed 

 three years before, that a great number of the meteors which 

 usually fall at that season are distinguished by their starting 

 from one point in the heavens, which is called their radiant 

 point. From the spasmodic manner in which they fall, he 

 inferred that their distribution in space must be very un- 

 equal ; and from the fact that there are many radiant points, 

 and that the meteors coming from any one radiant always 

 present the same color and appearance, he concluded that 

 there must be many rings of them revolving around the sun, 

 and that they become visible when the earth crosses their 

 orbits. 



He then proceeded to inquire how such a mass of cosmical 

 matter could have accumulated in the solar system. This 

 system seems to consist of two classes of bodies. First, the 

 jDlanets, all of which move in the same direction, and in near- 

 ly circular orbits, situated in almost the same plane, these 

 characteristics applying also to the satellites, with the excep- 

 tion of those of Uranus. Second, cometary bodies, which are 

 under no law as to the planes of their orbits or the direction 

 of their motions. These orbits are extremely elongated, and 

 extend far into stellar space, which seems to indicate that 

 they did not originally form part of our system, but are wan- 

 dering nebulae picked up by the sun. Reflecting on this view 

 of the case, Signor Schiaparelli was led to the hypothesis that 



