Curiosities of Science. 59 



heights and in various directions over the field of view, of fif- 

 teen minutes in diameter, of his twenty-feet reflecting tele- 

 scope. The field of view each time embraced only 8a smooth of 

 the whole heavens ; and it would therefore require, according 

 to Struve, eighty-three years to gauge the whole sphere by a 

 similar process. 



VELOCITY OF THE SOLAR SYSTEM. 



M. E. W. G. Struve gives as the splendid result of the 

 united studies of MM. Argelander, 0. Struve, and Peters, 

 grounded on observations made at the three Russian observa- 

 tories of Dorpat, Abo, and Pulkowa, "that the velocity of the 

 motion of the solar system in space is such that the sun, with 

 all the bodies which depend upon it, advances annually to- 

 wards the constellation Hercules* 1*623 times the radius of the 

 earth's orbit, or 33,550,000 geographical miles. The possible 

 error of this last number amounts to 1,733,000 geographical 

 miles, or to a seventh of the whole value. We may, then, wager 

 400,000 to 1 that the sun has a proper progressive motion, and 

 1 to 1 that it is comprised between the limits of thirty-eight 

 and twenty-nine millions of geographical miles." 



That is, taking 95,000,000 of English miles as the mean radius of 

 the Earth's orbit, we have 95 + 1 '623= 354-185 millions of miles; and 

 consequently, 



English Miles. 

 The velocity of the Solar System . 154,185,000 in the year. 



.... 422,424 in a day. 



,, .... 17,601 in an hour. 



,, ,, .... 293 in a minute. 



.... 57 in a second. 



The Sun and all his planets, primary and secondary, are therefore now 

 in rapid motion round an invisible focus. To that now dark and mys- 

 terious centre, from which no ray, however feeble, shines, we may in 

 another age point our telescopes, detecting perchance the great lu- 

 minary which controls our system and bounds its path : into that vast 

 orbit man, during the whole cycle of his race, may never be allowed to 

 round. North-British Review, No. 16. 



NATURE OF THE SUN. 



M. Arago has found, by experiments with the polariscope, 

 that the light of gaseous bodies is natural light when it issues 

 from the burning surface ; although this circumstance does not 

 prevent its subsequent complete polarisation, if subjected to 



* Sir William Herschel ascertained that our solar system is advancing to- 

 wards the constellation Hercules, or more accurately to a point in space whose 

 right ascension is 245 52' 80", and north polar distance 40 22'; and that the 

 quantity of this motion is such, that to an astronomer placed in Sirius, our sun 

 would appear to describe an arc of little more than a second every year. North- 

 British Review, No. 3. 



