for determining the difference of meridians , &c. 95 



July 13th. All the signals were visible to the naked eye. 



Rockets. 



App' Time I. 



II. 



III. 



Mean. 



I 



2 



3 

 4 

 S 

 6 



7 

 8 



9 

 10 



9" 31-55.8' 



9 51 55-75 



10 I 55.0 



II 57.4 



21 57.2 



31 56.6 



41 56.0 



51 55.8 



9^31- 55.6 » 



51 56.0 



10 I 55.2 



" 57-3 



21 57.0 



31 56.6 



41 56.0 



51 55.6 



11 I 56.2 



55.6' 



55.2 

 S4.8 

 57.6 

 57.0 

 56.5 

 5S.8 



55.3 

 56.2 



55.67. 



55-87 

 55.0 



57-43 

 57-07 

 56-57 

 55-93 

 55-57 

 56.2 



Comparison. Before - 

 After - 



Chronometer. 



9'' 16" 



II 13 



16'' 41" 16.63' 

 18 38 35-75 



Mean Error and Rate of Sidereal Clock. 



Mean of 6 * » 

 16'' 40" 



Mean error corresponding. 

 48-39' 



Mean rate. 

 + 0.14 



Comparison 12th to ditto 13th. Chronometer, + 0.87. 

 Chronometer fast 1° 19.86*. 



The 2d rocket was lost by all the observers : it did not appear till some seconds 

 after the time specified; and when it did appear it exploded immediately. It 

 exploded about 9'' 42" 22*. 



The loth rocket in column I. was lost by a derangement of the telescope. 



The third observation, column III. is doubtful to half a second. 



