12 PRESIDENT'S ADDRESS. 



and adds that at mid-day it was watched by crowds under 

 the impression that it was Halley's Comet, which had been 

 a very inferior object, and had disappeared from view at 

 6 o'clock in the morning! Several new canals and lakes 

 have been observed in Mars, and the rare occurrence of an 

 oblique belt in Jupiter was noticed in April and May, 1910. 

 The elements of 18 new minor planets discovered in 1909 

 have been worked out, bringing the number of these up to 

 more than 700. A total eclipse of the sun takes place on 

 April 28th, and by the time I read this (May 2nd) it will 

 doubtless be known whether success has attended the efforts of 

 the observers, there being only three stations suitable for their 

 purpose and those on islands in the Pacific. The total eclipse 

 of the moon on November 16th was an attractive sight, the 

 moon being of an unusually beautiful coppery colour. Obser- 

 vations in South Africa, with a view to determining the amount 

 of absorption of light by the atmosphere, give results differing 

 slightly from previous ones, and shew that about 17 per cent, 

 of all rays striking the atmosphere perpendicularly are 

 absorbed by it. A star in the zenith is 40 times as bright as 

 the same star on the horizon. In experiments as to the 

 absorption of light in its passage through water, it was found 

 that no trace of light could be detected on photographic 

 plates at a depth of 1,700 metres after an exposure of 2 hours, 

 though above that depth effects were produced, especially 

 by the blue and ultra-violet rays. Attempts are being made 

 towards a more general synchronisation of clocks over the 

 country, and will probably in course of time surmount the 

 difficulties, chiefly financial, which exist. In most countries 

 the time is now so arranged that it differs from that of Green- 

 wich by an exact number of hours, and French time has been 

 almost unique in being based on Paris local time, which is 

 9min. 21 sec. ahead of Greenwich. Quite recently, however, 

 in the present year a bill has become law by which Greenwich 

 time is in future to be used in France (except for naval, 

 astronomical, and cartographical purposes), and all the 

 French clocks were, on March 10th last, put back 9min. 21sec. 



