Mr. Ivory's Disquition on the Seconds Pendulum. 247 



other places. The length of the seconds pendulum at Rio in 

 latitude 22° 55' 22" S. was found as follows, 



inches. 



39-04381, Capt. Hall 

 39-04368, Mr. Foster 

 Mean .... 39-04374. 

 Now adopting the mean result as the length of the seconds 

 pendulum at Rio, and joining it instead of Captain Sabine's 

 experiment at Maranham to Captain Kater's experiments, we 

 shall find these results by the same method of calculation as 

 before, viz. 



= 1-85347/- 0-38645 

 A + 0-59932/— -13709 = <r 

 /= -20850 

 L = 39-01214 + <r. 

 Let us now vary the experiments, as under : 

 Station. 

 Rio de Janeiro 

 Paramatta . 

 New York 

 London . . 

 Unst. . . . 

 Spitzbergen 



Applying the same method of calculation to these six experi- 

 ments, the following results will be obtained, viz. 

 = 1-35189/- 0-28299 

 A + 0-53830/— 0-12464 = <r 

 /= -20933 

 L = 39-01196 + <r. 

 Finally, let us next combine a greater number of experiments, 



Latitude. 



Pendulum 



22° 55' 22" S. 



39-04374 



33 48 43 S. 



39-07696 



40 42 43 N. 



39-10168 



51 31 8 



39-13929 



60 45 28 



39-17146 



79 49 35 



39-21469 



VIZ. 



Station. 

 Maranham 

 Trinidad . 

 Bahia . . . 

 Madras . . 

 San Bias . . 

 Rio Janeiro 

 Paramatta . 

 Form enter a 

 New York . 

 Paris . . . 

 London . . 

 Leith . . . 

 Unst. . . . 

 Spitzbergen 



Latitude. 



2' 

 10 

 12 

 13 

 21 

 22 

 33 

 38 

 40 

 48 

 51 

 55 

 60 

 79 



31' 

 38 

 59 

 4 

 32 

 55 

 48 

 39 

 42 

 50 

 31 

 58 

 45 

 49 



43" S. 



56 N. 



21 S. 



9N. 



24 N. 



22 S. 



43 S. 



56 N. 



43 



14 



8 



37 



25 



58 



Pendulum. 



39-01214 



39-01884 



39-02425 



39-02338 



39-03881 



39-04374 



39-07696 



39-09424 



39-10168 



39-12929 



39-13929 



39-15554 



39-17146 



39-21469 



The 



