1823.] Philosophical Tramactionsfor 1823, Part I. 225 



tion respecting the measurement of an arc of the meridian in 

 India, ever prepared for the scientific world by its lamented 

 author ; his decease took place, as we are informed by the 

 Indian papers, on the 20th of January last, only eleven days after 

 the present communication had been read before the Royal So* 

 ciety. We shall, on this account, be more particular in our 

 analysis of these " Corrections," than, under circumstances of 

 less interest, we probably should have been. 



Col. Lambton first expresses his satisfaction at the results of 

 Capt. Kater's experiments in examining and comparing the dif 

 ferent standard scales ; and his pleasure on finding " that t\^c 

 Commissioners for considering the subject of weights and mea- 

 sures have adopted Mr. Bird*s scale of 1760, as by that means 

 there is now a universal standard of comparison, which applies 

 to the French metre, and to all the measures used on the Con 

 tinent." " From Capt. Kater's results it appears," the Col, 

 continues "that with respect to a measurement on the meridian, 

 the degree depending on my brass scale must be multiplied by 

 ,000018, and the product subtracted from the measure given, 

 by the scale, to reduce it to what it would have been, had it 

 been measured by what is now the Parliamentary standard ; 

 and the degree depending on Ramsden's bar, by ,Q0007, and 

 the product added to the measure given by the bar, to reduce 

 it to the standard measure." 



The arc which Col. Lambton measured, he next shows, de- 

 pends on both these standards ; and he then gives in succession 

 its different sections, correcting them by the above factors as 

 he proceeds. From these corrections we have th§ degree^ as 

 follows : 



X'athoms. 



« The degree for latitude 9° 34' 44''= 60477-09 



for latitude 13 2 55 = 60490-31 > Indian, 



for latitude 16 34 4!2 = 60511-65 



for latitude 47 30 46 = 60779-00 French, 



for latitude 52 2 20 = 60824-26 Endish. 



} 



o 



for latitude 66 20 12 = 60955-00 Swedish. 



" Then computing from Eq. 3, page 498, in the Phil. Trans. 



for 1818, Part II., we shall nave the ellipticity of the earth as 



follows : by the 



Indian and French, -rr^.^y ; to i-sr ; ttt, y t 5 Mean yrT^TT; 



Indian and English, -r^^^ ; ■^,-g^ ', ttt.tt 5 TrT,T€l 



Indian and Swedish, y^\-^ ; tot.tt ; ToiT^ 5 tot.tt; 



General Mean •jn^.-^T ; 



It is next shown, by means of a table computed from certain 

 data given in the paper, " that the first degree in latitude 

 9° 34' 44" by the measurement is 0-67 fathoms in defect j and 

 that the degree in latitude 16° 34' 42" (which may be taken for 

 16° 34' 44") by the measurement is 3*21 fathoms in excels." 



New Series, vol. vi. q 



