TRANSMISSION dF SOUNI> TBtftdtfttm iTolfO TUBES^ t^Q 



ground. On the other hanrl, vvheii the second observer 

 strikes at 30", the first observer reads 30" + r; and conse*' 

 quentty p 4- f indicates, beyond 30", the time in whlcH 

 the sodnd is transmitted to him. The quantitiies j9— -r andl 

 p-\-r therefore are given by these isochronous observa- 

 tions ; and half their sum immediately shows the titne of 

 transmission p, iudependant of the differences between 

 the watches, and iiiore exactly thanf- by direct obsterva- 

 tion. ■* •'' "■•I'-'- '■ •> ■•' • '' vi.-.'V _ 



In the experiments I triadis, the series of the ijuaiititi'iiS 

 •^i-^r and p 4- »* were as in the following table; ' ''''■ ''''-* 



p-^r p-{-T Siam,br 



Valueof2jJr 



let seriesj from 0^ 52' to O'' 39' —2" + 2-5" 0*5" 



2 2*5 D'5 



2 2*5 0-3 



2 2-5 0-5 



2 2-5 0-5 



2 2-5 0-5 

 :nr2-ji;-.; 2'5" 0*5^ 



^ -•>^ ' •2'5 0'5 



Sd series, frbm 1^ 27' to 1^32' - 2-S 3-3 0'7 



2-g 3-5 0-6 



3 3-5 0-5 

 2'9 3-5 0-6 

 3 3-3 0*5 

 3 3-3 '6'5 

 3 3*5 0-5 

 2-9 3-5 0-0 

 3 3-5 0'5 

 3 3-5 0-5 

 3*1 3*4 0-4 



Mean value of 2 j> 0*52 



Valueofp.»"»« ••*•*•••.. 0*26 

 This differs only 0*03" from' what we found above from This iieitlf 

 Ihe difFerence~of the transmissions: but the last method, as thelasmlcu. 

 it gives double th6 ijuantity to be deduced, deserves the lation. 

 jjreference. 

 If We add 0'26", the time of transmission through the 



sol id i 



