( 220 ) 



easily explained by tlie causes mentioned aliove. .So the question 

 regards more particularly the agreement in length of period and in 

 phase of the 14-monthly component. 



In the Archives NéerJandaises, Série II, Tome II p. 479 Dr. E. F. 

 VAN DE Sande Bakhuyzen gives a summary of deduced transits through 

 the positive axis of ,v, i e. through the Greenwich meridian. 



From my computations mentioned on p. 213 I have added to 

 this list two new epochs, one being deduced from the observations 

 of 1890.0 up to 1899.8, the other from those of 1899.9 up to 1907. 

 I compared the whole series with the elements obtained by E. F. van 

 DK Sande Bakhuyzen : 



Epoch = J. D. 2408567 1\ = 431''. 14. 



Representing the corrections of these elemei/ts respectively by 

 a and v, we arrive at the following equations : 



1. Washington 1^^' vert. 1862—67 ?/— 14 r — — 26'i /> = 2 



2. Pulkowa vert, c, Pol. 1863—70 u—13 t- = + 72 2 



3. Leyden, Fund, stars 1864—68 7^—12 i- = 2 



4. Leyden, Polaris 1864—74 ^^—12 v = — 8 2 



5. Greenw., Trans, circle 1865—72 w— 12 ^^ = -f 41 1 



6. Pulk., vert, c, Fund. st. 1863—75 u—10 /• — + 23 4 



7. Pulk., vert, c, Pol. 1871—75 z/— 8 v = -\- 28 2 



8. Pulk., 1-^ vert. 1875—82 //— 3 v = -{- W 2 



9. Pulk., vert. c. 1882—91 u-^ 'Ó v = ^ 6 4 

 JO. Greenw., trans, c. 1880—91 u-\- 3 v = -\- 9 1 



11. Madison 1883—90 m+ 5 y = — 18 1 



12. Lyons 1885—93 w+ 6 7; = — 2 2 



13. Albrecht-Zwiers J 890— 99 ii-{-10 v = — 'S 6 



14. Albrecht-Zwiers 1900—07 //+i9/- = -f30 8 

 The solution of these equations by the method of least squares, 



taking the weights p into consideration, gives: 



u = 4- 13^.42 c = + 0d.097 



so that the new elements become : 



Epoch =: .1. D. 2408580 J\ = 431^1.24. 



With these elements 1 tind the following residuals : 



