ASTRONOMICAL AND GEODETIC OBSERVATIONS. 



35 



Reduction of Pendulum Experiments made in July, 18G0, at Cambridge, Mass. 



race 4. 



Clock times, R. 



Arc. 



Temp. 



Clock times, L. 



Arc. 



U^ 51" 23''.21 



14 OT 02.81 



15 03 46.03 



16 06 14.16 

 IT 09 26.43 



17 56 48.14 



3°.15 

 2.84 

 1.50 

 0.81 

 0.48 

 0.33 



710.3 

 71.2 

 70.8 

 70.7 

 70.1 

 69.7 



11 



11 

 13 

 21 

 13 

 21 



13" 57" 

 14 07 



48". 25 

 27.91 

 35.26 

 59.38 

 05.57 

 31.20 



30.15 

 2.84 

 1.50 

 0.81 

 0.48 

 0.33 



29.80 

 29.78 



Face 2. 



9 

 11 

 15 

 13 



5 

 11 



9 

 11 



02 46.84 



05 27.28 



14 00.66 



22 43.68 



26 34.32 



39 07.65 



6 20 02.03 



7 .08 09.62 



3.70 



67.9 



15 



3.53 



68.0 



11 



3.15 



68.2 



19 





68.3 



15 

 5 



0.72 



70.0 



9 



0.50 



70.8 



9 



0.33 



72.2 



11 



1 



03 21.88 



05 56.31 



14 37.71 



23 24.65 



26 51.30 



39 32.79 



20 25.13 



08 34.74 



3.65 

 3.50 

 3.15 



0.72 

 0.50 

 0.33 



29.70 



Face 1. 



13 

 5 

 9 

 3 



15 

 7 

 5 



7 25 00.12 



7 27 28.52 



7 30 39.01 



7 38 34.30 



12 14 50.00 



12 17 54.51 



12 22 31.1-8 



4.45 



72.7 



9 



4,30 



72.8 



9 



4.17 



72.9 



9 





73.1 



3 



0.25 



72.7 



15 



0.23 



73.9 



11 



20 



72.3 



9 



7 25 25.13 



7 27 43.57 



7 30 58.02 



7 38 43.37 



12 15 28.99 



12 18 17.52 



12 22 50.21 



4.45 

 4.30 

 4.17 



0.25 

 0.23 

 0.20 



29.67 



Face 3. 



12 56 25.00| 

 — l.OOj 

 16 19 52.70 

 16 18 25.62 



3.40 



0.40 

 0.25 



72.0 



69.6 

 69.4 



12 



56 42.04} 



3.40 



— l.OOj 





20 07.60 



0.40 



18 36.70 



0.25 



29.72 



The following reduction gives, in the first place, the intervals of the clock times 

 obtained, for face 4, by subtracting the first mean from the fourth, the second from 

 the fifth, and the third from the sixth ; for face 2 by omitting the means at 4 hours 

 as they will contribute almost nothing to the accuracy of the result, and then pro- 

 ceeding as in the preceding case for face 4 ; for face 1 by the same treatment after 

 omitting the central mean, and for face 3 by subtracting the first from the second 

 and third means. 



These clock intervals are next reduced to mean time intervals by application of a 

 correction for rate (?•)• It was found convenient to apply this correction separately 

 for rate of clock on sidereal time, for which purpose a small table was computed 

 extending to 5 hours, and secondly for acceleration of sidereal on mean time. 



