93 
various British standards of linear measure. 
abridgement of Lieutenant Colonel Lambton’s very important 
operations, may be found in the Philosophical Transactions 
for 1818. 
The following are the data given by Colonel Lambton. 
The length of the degree due to 
Lat. 9 0 34' 44" is 60472,83 fathoms. 
13 2 55 60487,56 
16 34 42 60512,78 
By the French measurement, in 
Lat. 47 30 46 60779 fathoms 
By the English, in 
Lat. 52 2 20 60820 
By the Swedish, in 
Lat. 66 20 12 60955 
and by successively comparing the lengths of the European 
degrees with the three sections of the Indian arc, Colonel 
Lambton obtains for the compression 
By the French — - — 
j inf.72 100.7 
By the Swedish 
I 
1 
1 
mean 
1 
3 ° 5>73 
306,7 
3 >S »03 
3 ° 9’ I 5 
1 
1 
1 
mean 
1 
310,28 
311.36 
318.97 
313.54 
1 
1 
1 
mean 
1 
305.1+ 
305,72 
310,72 
307.19 
and the mean of the three means = 
309,96’ 
In order to reduce the preceding measurements to the 
English national standard, we have to multiply the fathoms 
of the Indian degree by — ,000018, and of the English by 
+ ,00007, to obtain the correction to be applied, with its 
proper sign, to the length of the degree. The French and 
Swedish degrees require no correction. 
We have then the following data for computation. 
