ERRATA. 



Page 344, line 2 from bottom, for " parallax," read " horizontal parallax." 

 ,, 407, ,, 2, for "the body," read " a fixed body." 

 ,, 410, ,, 'A, for "flo," read " dr." 



,, ' "dN" , "dN" 

 418, 13,/or read 

 ay due 



424, 4, for "1740," read "1747." 



,, ,, ,, 9, for " distance," read " disturbance." 



,, 426, ,, 20, for " (M" rearf " (A*" 



,, 428, ,, 21, same correction. 



431, ,, 8, /or "rate," read "ratio." 



,, 436, 24, /or "at," read "as." 



., 451, ,, 1, /or " accurate," read " inaccurate." 



