318 NOTES TO BOOK VII. 



has been much complained of lately. Some attempts have 

 been made to remedy this variety and disorder. M. Ar- 

 gelander has recently recorded stars, according to their 

 magnitudes as seen by the naked eye, in a Neue Urano- 

 metrie. 



Among representations of the Moon I may mention 

 Hevelius^s SelenograpMa, a work of former times, and Beer 

 and Madler's Map of the Moon, recently published. 



(BA.) p. 296. A few measures of double stars are 

 to be found in previous astronomical records. But the 

 epoch of the creation of this part of the science of astro- 

 nomy must be placed at the beginning of the present 

 century, when Sir William Herschel (in 1802) published 

 in the Phil. Trans, a Catalogue of 500 new nebulae of 

 various classes, and in the Phil. Trans. 1803, a paper 

 " On the changes in the relative situation of the Double 

 Stars in 25 years." In succeeding papers he pursued 

 the subject. In one in 1814 he noticed the break- 

 ing up of the Milky Way in different places, apparently 

 from some principle of Attraction ; and in this, and in 

 one in 1817, he published those remarkable views on the 

 distribution of the stars in our own cluster as forming 

 a large stratum, and on the connexion of stars and 

 nebulae (the stars appearing sometimes to be accompanied 

 by nebulae, sometimes to have absorbed a part of the 

 nebula, and sometimes to have been formed from nebulae) 

 which have been accepted and propounded by others as 

 the Nebular Theory. Sir William HerscheFs last paper 

 was a Catalogue of 145 new Double Stars communi- 

 cated to the Astronomical Society in 1822. In 1827 

 M. Struve of Dorpat, published his Catalogus Novus, con- 

 taining the places of 3112 double stars. While this was 



