OP A PENDULUM AT GREENWICH AND LONDON. 



93 



The ill accordance of the rates on the 18th — 19th and 19th — 20th, arises 

 in a great measure from an indifferent observation of the sun on the 19th ; and 

 further it appears, that about this time the transit instrument was veiy un- 

 steady, requiring adjustment both with regard to the meridian mark and level. 

 These circumstances, combined with the steady going of the clock before 

 and since this period, seem to justify the taking —0.54 as a mean rate for the 

 whole time; which has been accordingly employed with the following compa- 

 risons in the determination of the rate of the clock used in the experiments. 



1828. 

 May 15. 

 16. 



17. 

 18. 

 19. 



18. 

 19. 



Time by 



Clock. 



h m s 



23 15 

 23 35 



31 30 



1 44 30 

 1 55 30 



19 34 

 8 17 



Time by Sidereal 



Transit Clock. Interval, 



h m s h m s 



4 18 35.85, 



4 42 28.70 ;* 



5 42 57.78] :Ji 



6 59 59.5 H^^ 



7 14 51.20^ 

 52 20.31 



13 37 22.10 



23 52.85 

 29.08 



17 1.73 



14 51.69 



Mean 

 Interval, 

 h m s 



24 19 53.58 



24 56 23.82 



25 12 53.77 

 24 10 53.89 



Clock rate 

 in 24 hours. 



+6.34 

 -f-5.93 

 + 5.91 

 + 6.05 



}l2 45 1.79 12 42 56.75 +6.12 



For the subsequent part of the experiments, the following transits have bee 

 selected from the Greenwich Observations. 



1 



1828. 

 June4. Regulus. . 



|3 Leonis . 



SpicaVirg. 



ri Urs.Maj. 



g Bootis . . 



(SUrs.Min. 



a Cor, Bor. 

 June 5. Regulus. . 



a Urs.Maj. 



2 a Librae . 

 June7. Arcturus . 



aLibrae 



i} 



Observed /R. 

 h m s 



9 59 35.40 

 1 1 40 40.46 

 13 16 33.10 



13 41 8.92 



14 37 52.47 



14 51 42.00 



15 27 48.80 

 9 59 34.96 



10 53 24.47 

 14 41 47.23 

 14 8 11.80 

 14 41 34.88 

 14 41 46.30 



Apparent JR. 

 h m s 



9 59 13.74 



11 40 18.82 

 13 16 11.29 



13 40 47.35 



14 37 31.08 



14 51 20.42 



15 27 27.23 

 9 59 13.73 



10 53 3.33 

 14 41 25.96 

 14 7 51.68 



14 41 

 14 41 



14.50 

 25.96 



Error of Clock 



+ 21.66' 

 +21.64 

 +21.81 

 + 21.57 

 + 21.39 

 -j-21.58 

 + 21.57J 

 +21.23 

 + 21.14 

 + 21.27 

 +20.12 

 +20.38 

 -1-20.34 



Means 



Rate in 

 24 hours. 



at 13'' 22"^ 

 +2P.60 



at 111- 53"" 

 +21».21 



at 1 4'' 30-" 



+ 20'.28 



•0.42 



— 0.45 



Using these rates of the transit clock with the following comparisons of the 

 experimental clock, we get its rate. 



June 4. 

 5. 

 6. 



Time by 



Clock. 



h m s 



20 17 

 20 53 

 23 08 



Time by 

 Transit Clock, 

 h m s h 



2 36 48.74? 



3 16 44.44^:^^ 

 5 27 54.655"** 



Sidereal 

 Interval. 



Interval of 

 Mean Time. 



39 

 11 



55.70 

 10.21 



= 24 

 =26 



35 

 6 



53.68 

 53.31 



clock rate 

 in 24 hours. 



+ 6.15 

 + 6.16 



Thomas Glanville Taylor." 



