E. W. Morley— Oxygen in the Air. 173 
n 
urement with the apparatus. If we treat the second and third 
measurement in the same way, and compute the effect of these 
three probable errors on the final result, we get the numbers in 
the second column of the following table. 
Probable errors of measurements of gas, and of final results, occasioned by a probable 
error of the tenth of a miilimeter in each reading. 
In Analysis With Frankland 
cited from Bunsen. and Ward apparatus. 
0-046 % 
Tn measurement of air taken ---- - pe 
In measurement of air and hydrogen 0°050 
In measurement after explosion -- .- 0°039 0°031 
Probable error of result _....-...-- 0-051 0-038 
_ It is obvious that with the same error probable in each read- 
ing, the use of the rapidly working apparatus involves no 
ve 
sacrifice of accuracy to convenience, as far as the conditions 
of observation are concerned. 
ad 
‘B 
fae) 
4 
& 
5 
(a9) 
o 
. 
8 
1 
o 
4. 
> 
Fe 
A 
far) 
@ 
sn times more accurate than Bunsen’s, five places of logarithms 
distinguish smaller differences t servation deals with ; 
five places permit instant interpolation for hundredths of a 
