LONGITUDE OF McGILL OBSEEVATOEY, 



131 



Equations between AT', «, and r. from Observations at Montheal. — Confinucd 



The equations whicli follow, are derived by subtracting each mean equation for 

 the time stars from each of the equations for the polar stars. 



In the solution by least squares, only the normal equations are given. In the exact 

 solution of the two equations involving two unknown quantities, the final equation 

 involving either a or c is given, since the sine of the last divisor is an index of the 

 degree of precision which may be expected from the solution. 



