110 SCIENCE IN SHORT CHAPTERS. 



present month. Though eagerly looked for by astrono- 

 mers in all parts of the civilized world, they have been 

 seen no more since 1852. 



What, then, has become of them? Have they further 

 subdivided? Have they crumbled into meteoric dust? 

 Have they blazed or boiled into thin air? or have they 

 been dragged by some interfering gravitation into another 

 orbit? The last supposition is the most improbable, as 

 none of the visible inhabitants of space have come near 

 enough to disturb them. 



The possibility of a dissolution into smaller fragments is 

 suggested by the fact that, instead of the original single 

 comet, or the two fragments, meteoric showers have fallen 

 towards the earth at the time when it has crossed the orbit 

 of the original comet, and these showers have radiated from 

 that part of the heavens in which the comet should have 

 appeared. Such was the case with the magnificent display 

 of November 27th, and astronomers are inclining more and 

 more to the idea that comets and meteors have a common 

 origin the meteors are little comets, or comets are big 

 meteors. 



In the latest of the "Monthly Notices," of the Eoyal 

 Astronomical Society, published last week, is a paper by 

 Mr. Proctor, in which he expands the theory expounded 

 three years ago by an author whom your correspondent's 

 modesty prevents him from naming, viz., that the larger 

 planets Jupiter, Saturn, Uranus, and Neptune are 

 minor suns, ejecting meteoric matter from them by the op- 

 eration of forces similar to those producing the solar prom- 

 incences. 



Mr. Proctor subjects this bold hypothesis to mathematical 

 examination, and finds that the orbit of TempePs comet 

 and its companion meteors correspond to that which would 

 result from such an eruption occurring on the planet 

 Uranus. An eruptive force effecting a velocity of about 

 thirteen miles per second, which is vastly smaller than the 

 actually measured velocity of the matter of the solar erup- 

 tions, would be sufficient to thrust such meteoric or come- 

 tary matter beyond the reclaiming reach of the gravitation 

 of Uranus, and hand it over to the sun, to make just such 



