1882.] 



President's A ddress. 



323 



well as to the comets. Professor Henry Draper and Mr. Common 

 have obtained photographs of the great nebula in Orion, showing 

 considerable detail, and Mr. Huggins and Professor Henry Draper 

 have succeeded in photographing its spectrum. Mr. Huggins finds in 

 his photograph a very strong bright line in the ultra-violet at wave- 

 length 3730, in addition to the four nebular lines previously discovered 

 by him in the visible portion. Professor H. Draper's photographs do 

 not show this bright line, though they have faint traces of other lines 

 in the violet, and he thinks that this may be due either to the circum- 

 stance that he had placed himself on a different part of the nebula or 

 to his use of a refractor with glass prism, while Mr. Huggins used a 

 reflector and Iceland spar prism. The most striking feature of Pro- 

 fessor Draper's photographs is perhaps the discovery of two condensed 

 portions of the nebula (just preceding the Trapezium) which give a 

 continuous spectrum. 



Professor Schiaparelli has recently called attention to a peculiar 

 feature on the planet Mars. In 1877 he remarked a number of 

 narrow dark lines, which he called " canals," connecting the dark 

 spots or so-called "seas" of the.southern and northern hemispheres. 

 He now finds that these lines are each doubled, so that according to 

 his view the equatorial regions of Mars are covered by a network of 

 pairs of parallel straight lines. It is to be remarked that though 

 the appearance of Mars as depicted by Professor Schiaparelli differs 

 greatly from previous representations, indications of these double 

 " canals " are to be found in the sketches of other observers. 



The two bright comets of this year possess more than usual interest. 

 The bright comet discovered at Boston by Wells, on March 18th, was 

 the first comet since the spectroscope was applied to these objects, 

 which presented a spectrum unlike the hydrocarbon type common to 

 all the other comets which appeared since 1864. The eye observa- 

 tions, as well as its photographic spectrum (taken by Mr. Huggins), 

 showed an absence of the hydrocarbon spectrum, which was replaced 

 by a brilliant continuous spectrum and bright lines, including those of 

 sodium. 



In September, a very brilliant comet appeared near the sun. It 

 seems to have been discovered independently by Ellery, at Melbourne, 

 Finlay at the Cape, Mr. Common in this country, and also by Thollon 

 and Cruls. This great comet has been a brilliant object in the early 

 mornings during the past two months. On September 17th, an 

 observation, apparently unique in the history of astronomy, was made 

 by Mr. Gill at the Cape, w T ho watched the comet right up to the sun's 

 limb. It could not, however, be detected in the sun, and this circum- 

 stance of appearing neither bright nor dark when in front of the sun, 

 appears to suggest a very small substantiality, or great separation of 

 the cometary matter. After perihelion it presented a magnificent 



