36 PROCEEDINGS OF SECTION A. 



of the fixed stars that have been examined, and hydrogen, we 

 know, is an important component in very many stars. It may 

 thus be that meteoric matter is a tangible connecting link 

 between the solar system and the rest of the visible universe 

 across that great wilderness of space by which they are separated. 

 Some very important suggestions by Mr. Norman Lockyer uj^on 

 the classification of heavenly bodies, and I may almost say a new 

 theory of the universe, have been laid before the scientific public 

 through the Royal Society of London. In brief it may be stated 

 as follows : — Space is a plenum of meteoric matter. All self- 

 luminous bodies in the celestial spaces are composed of meteorites 

 or meteoric vapour produced by heat from condensation of meteor 

 swai'ms due to gravity. He assumes some at least of the meteoric 

 matter to have orbital motion. Some may be in motion, some at 

 rest, but all visible evidence of this matter appears as stars, 

 comets, or nebulae, between which no distinction can be made on 

 physical grounds. Visibility is brought about by collisions of 

 meteoric particles, and according to the profusion of sparseness of 

 the meteoric particles in space, where collisions occur by inter- 

 sections of orbits with matter at rest or with bodies in other 

 orbits, we have nebulse of the several kinds, comets, nebulous 

 stars, and even concrete stars themselves. This may be called the 

 meteoric hypotheses, and as the conception has for its foundation 

 a mass of indisputable facts, the result of long and laborious 

 research with the spectroscope in the laboratory, compared 

 skilfully and patiently with facts revealed by spectroscopic 

 examination of all classes of celestial objects, I can but regard it 

 as a most important step in physical astronomy, destined, I 

 believe, to make a new epoch in tlie science. The idea that 

 meteoric matter or bodies pervade all space is not in itself a new 

 one, for when we consider (accepting Professor Newton's estimate) 

 that 20,000,000 meteorites fall to our earth daily, it is evident 

 that space is, astronomically speaking, full of them ; nevertheless, 

 by the same calculation by which Professor Newton arrived at 

 the foregoing number, he ascertained that sparseness to be such 

 that the meteorites must be 250 miles from each other in space. 

 As regards the effects of collisions of meteorites, the speed of 

 visible meteors can be measured, and it is reckoned to be at an 

 average 30 miles a second. If, then, the specific heat of the 

 material of which they are composed is "10, the increase of 

 temperature when their motion was arrested by a full collision 

 would amount to 2,700,000 degrees centigrade (steel being fluid 

 at 3,552deg. Fahr). 



In conclusion, I now come to the question of recent methods of 

 research in observational astronomy and the ditficulties in the way 

 of future progress. 



The telescope, of course, is the chief instrument of the 

 astronomer, and it has been brought to a stage of great perfection, 

 yet at its best it is very far from what is wanted. 



