as deduced from Experiments made with the Pendulum. Q5 



least favourable supposition, or that which gives the greatest 

 errors ; the observed pendulum at Ascension exceeds calcula- 

 tion no less than '008 in. ; at Trinidad the error is very small ; 

 and although the observed pendulums are greater than calcu- 

 lation at all the other stations, yet the errors are much smaller 

 than they were in the case of the first equatorial pendulum. 

 We may conclude from this comparison that, from some local 

 anomaly which is probably explained in the original work of 

 the author, the experiments at St. Thomas and Ascension are 

 irreconcileable with the rest, and it will be advisable to leave 

 them out. Beginning at Maranham we cannot obtain a good 

 determination of the ellipticity by combining it with any of the 

 stations, in the table till we come to New York, the variation 

 in the length of the pendulum being too small. If we com- 

 bine it with New York, and each of the five more northerly 

 stations we obtain the results set down in the table. The cal- 

 culations may be made by (2), which applies in every case; 

 but when Maranham is combined with any other station, it 

 will be shorter to use (1), making L = 39-01175. The six 

 results are pretty regular, the mean of all being -00333. 



Stations. 



Latitude. 



Pendulum. 



Elliptic. 



Maranham 

 and 



St. Thomas 



Maranham . 



Ascension . . 



Sierra Lieone 



Trinidad . . 



Bahia .... 



Jamaica . . . 

 "New York . 



London. . . 



Drontheim . 



Hammerfest 



Greenland . 

 w Spitzbergen . 



0°24 4l"N. 

 2 31 43 S. 



7 55 48 S. 



8 29 28 N. 

 10 38 56 N. 

 12 59 21 S. 

 17 56 7N. 

 40 42 43 



51 31 8 

 63 25 54 

 70 40 5 

 74 32 19 

 79 49 58 



Inches. 

 39-02074 

 39-01214 

 39-02410 

 39-01997 

 39-01884 

 39-02425 

 39-03510 

 39-10168 

 39-13910 

 39-17456 

 39-19519 

 39-20335 

 39-21469 

 Mean . . 



•00323 

 •00332 

 •00343 

 •00337 

 •00336 

 •00328 





•00333 



New York and Spitzbergen 



Sierra Leone and . . \ •„. 

 (_ Spitz 



Trinidad and . . . . < q . ' 



T t f Greei 

 Jamaica and .... < q . 









•00332 

 •00347 

 •00338 

 •00337 

 •00328 

 •00344 

 •00334 

 •00348 

 •00339 



nland . . . 

 jergen . . 

 iland . . . 

 Dergen . . 

 nland . . . 

 jergen . . 

 nland . . . 

 jergen . . 















In 



