the Barometric Formulce, ^c. 



639 



Table IV. 



Showing Ihe Errors of Ileighis of Convent of Saint Bernard above Observatory of Geneva, calculated 

 from Observations made when, according to large Table of Horary Correction, the Horary Cor- 

 rections vanish. The calculated Heights are less than true Heights (= 2070'34 Metres). 



A.m. 



Errors. 



January • ■ 



February, I 10 



March, . . 

 April, . . 

 May, . . . 

 June, . . 

 July, . . 

 August, 

 September, . 

 October, 

 November, . 

 December, . 



8 30 



Mean of nine months, 



February to Octobe: 



■:} 



20 



48 

 30 

 30 

 8 

 15 

 20 



14 04 

 7-24 

 4-21 

 10-00 

 14-34 

 16-63 

 10-97 

 11-62 

 19-91 



12-106 



P. M. 



M. 





 

 

 

 15 

 



8 35 

 8 

 6 20 

 4 27 

 10 



Errors. 



Metres. 



1-76 

 13-44 



8-91 



7 09 

 14-82 

 13 26 

 12-53 



9 05 

 11-05 

 18-55 

 17-84 



12-100 



One moment only. 



One moment only. 

 No moment whatever. 



{Mean of nine months, Fe- 

 bruary to October. 



Every person -who may inspect the foregoing small Table -will doubtless be 

 surprised at perceiving, that although the mean of errors for the nine months 

 between February and October (both inclusive), for the forenoon and after- 

 noon, are very nearly equal (the one being 12-106 metres, the other being 

 12100 metres), yet the errors for different months are strikingly different: for 

 instance, the error of the month April of the forenoon is only 4-21 metres, but the 

 corresponding error of the mouth October is as much as 19-91 metres. How- 

 ever, the errors of forenoon and afternoon are for the same month nearly equal. 

 Now it is to be remarked, that according to the Table of Horary Corrections, 

 I had reason to expect such errors to be little removed from nothing. Great, 

 therefore, was my disappointment. Yet there is this consolation in such dis- 

 appointment, that had the formula of Laplace, or any other derived from La- 

 place's (such as Bayley's or Poisson's), been employed instead of my own 

 formula, the errors had been double of the actual errors, as given in tlie small 



VOL. XXIII. 4 P 



