450 THE YARD, PENDULUM, AND METRE. 



cimalized denominations which anybody might agree to 

 buy, sell, or contract by, permissive. There seems to be 

 a doubt whether such is now the case, and if so the law 

 should I think be altered. But I would leave untouched 

 all our present denominations and their relations to the 

 standard and the only new measure I would legalize 

 would be a " module" (or some other name at present un- 

 occupied} of 50 geometrical inches being the ten millionth 

 of the polar axis, or its half, the "geometrical cubit" of 

 25 such inches leaving its use quite voluntary. 



COLLINGWOOD, Sept. 30, 1863. 



ADDENDUM. 



(33.) Since the foregoing remarks were written my 

 attention has been called by the Astronomer Royal to 

 a very elaborate memoir by Captain Clarke, in vol. 

 xxix. of the Memoirs of the Royal Astronomical Society, 

 whose conclusions, though differing from those of M. 

 Schubert in some particulars (as in making the equator 

 more elliptic) yet, so far as the present subject is con- 

 cerned, tend in the same direction, and that, as regards 

 .he aliquot error of the metre, even more strongly. 



(34.) Captain Clarke assigns for the three axes of the 

 earth the following values :- 



Polar axis 41,707,536 feet 



Or in inches 500,490,432. 



Longer equatorial axis 41,852,970 feet. 



Shorter do. do 41,842,354 



