Q/i. the Motion of the Sun and Solar System, 231 



several detached papers. . The changes which have taken 

 place in the relative position of double stars, have ascer- 

 tained i^iotions in maKV of them, which are prebably of the 

 s&me nature with those that have hitherto been called pro- 

 per motions. Jt is well known that many of the principal 

 stars have been found to have changed their situation, and 

 we liave lately had a most valuable acquisition in Dr. Mas- 

 kelvne's table of proper motions of slK-and-tr..irty of them. 

 If this table affords us a proof of the motion of the stars of 

 the tirsit brightness, such as are probably in our immediate ^ 

 ceighbourlioed, the changes of the position of minute ' 

 jdouhle stars that I have ascertained, many of which can 

 •only be seen by the best telescopes, likewise prove ihat mo- 

 lions are equallv carried on in the remotest parts of space 

 which hitheito we hav-c been aiile^to .penetrate. 



'I'he proper motions of the stars have long engaged the 

 attention of astronomers, and in tlie year 17S3 I deduced 

 from them, with a high degree of probabiHty., a motion of 

 't.hesun and solar system towards X Herculis. The reasoTis 

 which were then pointed out for introducing a solar mo- 

 tion, will now be much strengthened by additional consi- 

 derations ; and die above-mentioned table of well-ascer- 

 tained proper motions wiU also enable us to enter rigo- 

 Touslv into the necessan,' calculations for ascertaining its 

 <lirection, and discovering its velocity. When these points 

 are established, we shall be prepared to draw some conse- 

 <juences from them that will account for many phsenomena 

 which otherwise cannot he explained. 



The scope of this paper, Vv'herein it is intended to assign. 

 •not only the direction, but also the velocity of the solar 

 niotion, embraces an extensive field of observation and cal- 

 culation ; but as to give the who-le of it would exceed the 

 compass of the present sheets, I shail reserve the velocity 

 <A' the solar motion for an early future opportunity, and 

 proceed now to a disquisition of the first part of my sub- 

 ject, which is the dii-cctiou of the motion of the sun and 

 solar systena- 



Beasons for admitting a Solar Motion. 



It mav appear singular that, after having already long ago 

 pointed out a solar motion, and even fixed upon a star to- 

 wards which I supposed it to be directed, I should again 

 think it necessary to show that we have many substantial 

 reasons for admitting such a motion at all. What has in- 

 <lui;cd me to caLer ialo this inquiry is, that some of the 

 1> 4 coiisequeaccs 



