54 



ON THE PROPERTIES OP MATTER, 



satellites upon a planet : and Dr. Herschel gives instances of all these phai- 

 nomena actually completed, or in a train of completion, in different parts 

 of the visible heavens. 



Such he submits as his latest opinion of the general construction of the 

 heavens ; beheving stars, planets, and comets to have originated, and to be 

 still originating, from such a source ; the nebulous matter contained in a 

 cubical space seen under an angle of ten degrees demanding a condensa- 

 tion of two trillion and two hundred and eight thousand billion times before 

 it can be so concentrated as to constitute a globe of the diameter and 

 density of our sun. 



Some of these masses of light are indistinct and barely^visible even by Dr. 

 Herschel's forty feet telescope ; and he hence calculates,i;hat if a mass thus 

 traced out contain a cluster of five thousand stars, they must be eleven 

 milhons of millions of millions of miles off. M. Huygens entertained an 

 analogous idea ; and conceived that there are stars so immensely remote 

 that their hght, although travelling at the rate of eleven millions of miles in 

 a minute, and having thus continued to travel from the formation of the 

 earth, or for nearly six thousand years, has not yet reached us. 



But this sublime conception is of much earher origin ; and it is due to 

 the magnificence of the Epicurean scheme to state that it is to be found 

 completely developed among its principles. Lucretius has beautifully 

 alluded to it in lines of which I must beg your acceptance of the following 

 feeble translation, the only difference being, that lightning or the electric 

 fluid, is here employed instead of light, at least by Havercamp ; for Vossius, 

 in the Ley den edition, gives us light for lightnings reading lumina instead 

 offulmina. 



The poet is speaking of the immensity of space : — 



The vast whole 



What fancied scene can beund ? O'er its broad realm, 

 Immeasur'd, and immeasurably spread, 



From age to age resplendent lightnings urge, • 

 In Tain, their flight perpetual ; di&tant, still. 

 And ever distant from the verge of things. 

 So vast the space or opening space that swells^ 

 Through every part so infinite alike.* 



From this immense range of nebulous light Dr. Herschel derives comets 

 as well as stars and planets, believing them, indeed, to be the rudiments 

 of the two latter ; and he has especially noticed, as originating from this 

 source, the well remembered comet that so brilliantly, and for so long a 

 period of time, visited our horizon during the close of the year 1811; 

 which he conceives will be converted into a stellar or planetary orb as soon 

 as its luminous matter, and especially that of its enormous tail, shall be 

 sufliciently concentrated for this purpose. This tail he calculated, when 

 at its greatest apparent stretch in October of the same year, at something 

 more than a hundred millions of miles long, and nearly fifteen millions 



* Omne quidem vero nihil est quod finiat extra. 

 Est igitur natura loci, spatiumque profundi, 

 Quod neque clara suo percurrere fulmina cursu 

 _ Perpetuo possint aevi labentia tractu ^ 



Nec prorsum facere, ut restet minus ire, meando 

 Usque adeo passim patet ingens copia rebus, 

 FinibUs exemptis, in cunctas undique parteis.t 



•s- -De Ker. Nat. j. 1000, 



