52 Captain Kater/s account , &c. 
“ centre of oscillation round C may be made to fall in c, 
“ which is known by the oscillations on C and c being 
“ isochronous. Therefore the distance of the edges is equal 
“ to the length of the simple pendulum which is isochronous 
“ with this compound pendulum.” 
Although it does not appear that this idea was ever put in 
practice, it is evident, from the above extract, that the first 
proposal to determine the length of the seconds pendulum 
by means of the convertible pendulum, belongs to Professor 
Bohnenberger, and I take the earliest opportunity of ac™ 
knowledging his claims, in order that the credit of the first 
suggestion may rest where it is so justly due. 
London, 31st December, 1825, 
