ASTRONOMICAL AND GEODETIC OBSERVATIONS. 



41 



flECAPITUIiATION OF OBSERVED CORRECTION OP PoCKET CHRONOMETER AT PORT FOULKE, IN 

 CONNECTION WITH PENDULUM EXPERIMENTS. 



1860. September 22 at ll"" chronometer time 



1860. 



October 



1 



11 



1860. 



October 



2 



11 



1860. 



October 



9 



11 



1860. 



October 



10 



11 



1860. 



October 



n 



10 



aT on mean time. 



—50" 



43».3±0».9 



—50 



58.4 0.9' 



—48 



46.8 O.t 



—48 



54.9 0.6 



—48 



50.1 1.1 



—48 



58.5 0.7 



The chronometer changed its correction about 2™. 2 between 9 A. M. and 3 P. M., 

 October 2d ; retarded or stopped in consequence of a hair having become entangled 

 in one of the hands. 



The actual rate of the pocket chronometer, during the pendulum experiments, is 

 found by means of comparisons of the pocket chronometer with three mean time 

 chronometers ; comparisons were made at the beginning and end of each daily set 

 of pendulum experiments. 



Chronometer comparisons for correction and rate of mean time chronometers 

 2007, 1062, and 740. (Those for September 22d have already been given.) 







October 1, 1860. 





Pbcket chronometer. Mean time. 



Chronometers. A T" at Port Foulke 



11'' 25'" 24^0 



10" 34'" 25^6 



2007 : 3" 26"' 



—4" 51" 



34^4 



26 54.0 



10 35 55.6 



1062 : 3 25 



—4 49 



04.4 



28 31.2 



10 37 32.8 



740: 3 27 



—4 49 



27.2 





October 2, 1860. 





Pocket chronometer. Mean time. 



Chronometers. a 7" 





11" 02'" 15».3 



10" 13" 28^5 



2007: 3" 05-" 



—4" 51" 



3P.5 



2 43.5 



10 13 56.7 



1062: 3 03 



—4 49 



03.3 



4 21.0 



10 15 34.2 



740: 3 05 



—4 49 



25.8 





October 9, 1860. 





Pocket chronometer. Mean time. 



Chronometers. aT 





10" 39"' 02^0 



9" 50"'07M 



2007 : 2" 41" 



—4" 50" 



52».9 



39 41.9 



9 50 47.0 



1062: 2 40 



—4 49 



13.0 



41 21.9 



9 52 27.0 



740: 2 42 



—4 49 



33,0 





October 10, 1860. 





Pocket chronometer. Mean time. 



Clironometers. aT 





10" 52-" 04».0 



10" 03"" 13^9 



2007 : 2" 54"' 



—4" 50" 



46M 



52 42.2 



10 03 52.1 



1062: 2 53 



—4 49 



07.9 



53 22.5* 



10 04 32.4 



740 : 2 54 



—4 49 



27.6 



Two sets -of comparisons were 

 talien, according within a frac- 

 tion of a second. The value 

 given is the mean. 



Two sets of comparisons were 

 taken ; they do not differ by 

 more than 0^2. 



Two sets were taken ; greatest 

 difference 0^4; the mean is 

 here ffiven. 



Pocket chronometer. Mean time. 

 10" 05" 23^0 



06 51.4 



07 32.1 



October 17, 1860. 

 Chronometers. a T 



9" 



16" 



24^5 



9 



17 



52.9 



9 



18 



33.6 



2007: 2" 7" 



1062: 2 7 



740: 2 8 



—4" 50" 35^5 

 —4 49 07.1 

 —4 49 26.4 



Mean of two sets ; values do not 

 differ by more than a fraction of 

 a second. 



October 31, 186'0. a T Pocket chronometer ^ 49" 15^2 ± 0^7. 



Pocket chronometer. Mean time. 



9" 24" 50^0 



25 53.6 



26 39.0 



8" 3.5" 34'. 8 

 8 36 38.4 

 8 37 23.8 



Chronometers. 

 2007 : 1" 26" 

 1062: 1 26 



740: 1 27 



aT 



-4" 50" 2.5^2 

 -4 49 21.6 

 -4 49 36.2 , 



