Ixviii. PRESIDENT'S ADDRESS. 



require confirmation. The diameter of Neptune, the furthest 

 of our planets from the sun, has been measured and found to be 

 about 50,000 kilometres. The period of rotation of Uranus 

 has also been found to be 10 hours 45 min. The number of 

 known minor planets has now risen to 732. Several meteorites 

 of interest have been recorded. A wedge-shaped fragment of 

 a meteorite, weighing about 1,900 grams, was found in 

 Kansas, U.S.A. ; on Dec. 18 a bright meteor was seen by 

 several observers at Manchester and in Yorkshire. It is 

 described as having a diameter half the size of the moon, and 

 leaving a bluish trail. After travelling some distance it 

 divided into two portions, of which one seemed to fall towards 

 the earth and the other to continue its course. A large 

 detonating meteor passed over Patagonia on Feb. 10, and 

 was seen and heard over a considerable area. But the most 

 interesting occurrence was a shower of meteoric stones near 

 Holbrook, Arizona, on July 19 last. A large meteor was 

 seen to pass over Holbrook with a loud noise which lasted for 

 about half a minute, and numerous stones were seen to 

 fall near Aztec, raising puffs of dust in the sandy desert, 

 more than 14,000 being found, weighing from one gram 

 to 141b., over an area of three miles by half a mile. It 

 seems probable that the new comet 1912b may be identical 

 with the Tuttle comet, which, approaching Jupiter too 

 closely, has had its course shortened by 86 days. The spectra 

 of Nova Geminorum and Nova Persei have been successfully 

 obtained and carefully studied, and appear to present no 

 striking differences from each other or from those of Nova? 

 in general. Hydrogen is the chief feature, with calcium, 

 iron, and other constituents. A recent theory with regard 

 to temporary stars, or one class of Novse, is that the star has 

 somewhat cooled down, and a thin crust has formed over its 

 surface. A break occurs in the crust, and the liquid fiery 

 contents flow out in a sort of gigantic volcano. This produces 

 the appearance of a temporary star, and may occur at 

 intervals. The Pole star has been believed to be variable, 

 and from measures secured on 17 nights a variation of 0'078 



