PRESIDENT'S ADDRESS. 9 



bodies concerned ; but further experiments have produced 

 negative results, so that the theory is, so far, very doubtful. 

 Rotation has been observed in several more nebulae during 

 the past year, and the dimensions of the Ring Nebula in Lyra 

 have been computed to be no less than 330 and 250 times the 

 diameter of Neptune's orbit in the longer and shorter axes 

 of the ellipse. This was done by ascertaining the parallax 

 of a star which is associated with the nebula in question. 

 The nearest star to our system is star Centauri, and a faint 

 star in the same constellation has now been found to be at 

 almost exactly the same distance from us. By a spectroscopic 

 method it has been shewn that a definite decrease in the 

 brightness of stars is almost certainly accompanied by an 

 increase in velocity. Many stars have been shewn to possess 

 proper motion of their own. Amongst others one of the 14th 

 magnitude near 8 Arietis has the large proper motion of 

 l'74in. per annum. The total number of stars down to the 

 16th magnitude has been estimated at 33,000,000. A small 

 new star associated with a nebula in Cygnus has been dis- 

 covered, and several others, including one, also associated 

 with a nebula, in Andromeda. In this nebula no less than 

 five novae have been noted of late years. .A total eclipse of 

 the sun will take place on June 8th next, the totality lasting 

 from one to two minutes over a belt about 60 miles wide 

 stretching from Washington to Florida. Owing to the war no 

 English expeditions for its observation have been organised ; 

 but there will be some American ones. A solar prominence 

 of unusual magnitude was observed on May 26th, 1916, 

 which attained a height of half a million miles and a velocity 

 of 457 kilometres per second, and then faded very rapidly. 

 These prominences have been considered to be connected with 

 sunspots ; but some observations, extending from 1904 to 

 the present time, have not shewn this to be the case. On 

 December 3rd last, a meteorite fell in Perthshire, exploding 

 with great noise. Three portions were found, one of 22Jlb., 

 which penetrated the earth to a depth of 20in., one of 2Jlb., 

 which struck the lodge at Keithick House, Coupar Angus, and 



