SOLAR MOtlON. 241 



The contents of this Table will enable us to examine investi^atioa 

 the motions of the stars in different points of view. For of the proper 

 instance, by the apparent motions in the third column, ^^^^^ 

 and their directions in the fourth, a figure may be drawn 

 which will represent the actual state of the heavens, with 

 respect to those annual changes in the situations of our 

 36 stars, which in astronomical tables are called their 

 proper motions. 



Fig* 1, Plate VI. gives us these motions brought into 

 one view, so that by supposing successively every one of 

 the stars to be represented by the central point of the 

 figure, we may see the angular quantity and direction of 

 the several annual proper motions represented by the 

 line which is drawn from the centre to each star. By this 

 means wc have the comparative arrangement and quantity 

 of fuese movements with respect to their directions. 



Fig. 3 represents the same motions, but instead of be- 

 ing drawn so as to show theit directions with regard to 

 the several meridians and parallels of the stars, they are 

 laid down by the angles contained in the fifth column ; 

 and will therefore indicate their arrangement with re- 

 spect to a line drawn from the solar apex toward the 

 parallactic centre. These directions will remain the 

 same, whatever may be the velocity of the solar motion 

 upon which we shall ultimately fix, provided no change be 

 made in the situation of the apex toward which the sun 

 ha^ been admitted to move. 



In these two figures, the lines drawn from the centre 

 give us only the angular changes of the places that have, 

 been either observed or calculated, and not the velocities 

 which are required in the stars to produce them. It will 

 therefore be necessary to represent the velocities by two 

 other figures, in which the same directions are preserved, 

 but where the extent of each line is made proportional to 

 the distance of the stars in the second column. 



Fig. 2 is drawn according to this plan; the angles of 

 the directions remain as in the fourth column, but the 

 lines are lengthened so as to give us the velocities con- 

 tained in the sixth. 



In Fig. 4, the angles of the 3d figure are preserved, 

 'but the liaes are again lengthened as in Fig, 2. 



N, B. The&e 



