﻿34 



Table IV.^Kesults ;it Melbourne and Christchurch. 



§ C. The period.s observed at Kew in 1901 and 1904 have been already given. Their mean values, 

 uncorrected for flexure, are 



Pendulum 

 Period . . 



.37 



0-. 5087776 



.'58 

 0^ 5087732 



39 



• .5088064 



It has been judged best to employ these mean Kew values for comparison with the results obtained at 

 Winter Quarters and Christchurch, but to employ only the 1901 results for compaiison with Melbourne. 



The observations made at Christchurch in 1904 gave lower values than those obtained in 1901, the 

 ditt'erences in the seventh place of decimals being - 20 for No. 37, - 61 for No. 38, and - 138 for No. 39. 

 The differences for Nos. 37 and 38 give a mean which is closely similar to the corresponding mean 

 difference observed at Kew, thus suggesting that any change that took place in these two pendulums 

 occurred at Winter Quarters, and so influenced the Kew and Christchurch observations alike, leaving the 

 Melbourne observations unaffected. The comparative brevity of the interval between the oliservations 

 made at Kew and Mel!)ourne in 1901 is an argument pointing in the same direction. 



§ 7. If /i and t> denote the periods of a pendulum at two places where ;/i and [/-^ are the values of gravity, 

 then, assuming the pendulums unchanged, and the conditions as to temperature, pressure, &c., the same at 

 the two places, we have 



Uih- = f/Jr, 

 or 



;/.■ = ,'/! (/i/^.)'- 



Accepting 981 '200 (centimetre/second") as the value at Kew,* the values deduced ))y the above formula 

 for Melbourne, Christchurch, and Winter Quarters are those given in Table V. under the heading 

 " Oljserved values." In the probable mean the results from pendulum No. 39 have been allowed only half 

 weight as compaicd to those from either 37 or 38. 



Table V. 



' Roy, Soc. Proc.,' A, vol. 78, .19u6, [i. 245, 



