® 
Essay on the Figure of the Earth. 47 
ble value was determined from them all, there still remained from 
the separate measures 0 ares, deviations which could not be as- 
cribed to errors of observat 
neg ig investigation iat shown that the old measurement 
of a degree by Maupertuis and Outhier was considerably in error. 
Rosenberg and Swanberg obtained quite different values. In 
7 
Liesganig, Beccaria and others in the eighteenth century could 
not bear severe criticism nor stand side by side with the better 
and approved a ares. AA more a and reliable coefficient of 
compression still remains a desidera 
€ insert here for comparison sb vale of the pws. 
_ 48 they result, for the most part, from the same measures 
according to different methods of reduction, in the first four ie 
cades of this centur ry. 
Semi-major axis ; Semi-minor axis vempeee? Coeff. of | 
in toises. in toises. toises. compression. 
Walbek, - - | 3271742°8 | 3260989°3 107855 sun-rs 
Schmidt, - - | 3271852:3 | 3260853-7 | 10998-6 orice 
Bessel, (L.), - | 32719539 | 3261072°9 | 10881:0 | s5¢70 
As Bessel afterwards discovered an error in Delambre’s French 
triangulation which could not be without influence on the com- 
band result, he repeated his reduction with this correction and 
oun 
Bessel, (II), - | 3272077:1 | 3261139°3 | 10937°8 | ay¢-rs 
si og ia to the last reduction, the probable error is three 
as great as the difference of Bessel (1) and Bessel (II). 
Pence in this even the best measures of this sort do not yield 
sufficiently accordant baie it was attempted to find the com- 
er a: = two other ways. The observations of the pendulum 
con sen tee of the earth’s compression, different 
Iengths. of — seconds pendulum in different latitudes, and 
e 
of se such SS pte gi yet still the result (571.55) fluctuated be- 
een ¢ mits, eS 
he te s ig? it weigh the compression was not without 
influence, was also resorted to, and gave 3}, for the compression, 
but on account of the smallness of the aggregate effect it is of 
inferior accuracy. 
We have found it necessary to present this general view in 
order to dean the limit of the results arrived at by preceding 
result depends, in a measure, on the law of density of the earth in passing 
from the Surface to the centre. 
