58 Notices respecting New Books. 
produces the effect, that when it is combined with any body it 
continually tends to elevate it, and in this way overcome that 
force (gravitation) which retains it, and would precipitate it to- 
wards the earth.” 
Iam, I repeat, the more anxious to establish this view, be- 
cause I am convinced it affords the only satisfactory explanation 
of the operations and phenomena of nature and art, It is ne- 
cessary to prove this, and first by an examination of Galvanism. 
~ Rag York, July 15, 1818. 
[To be continued. ] 
IX. Notices respecting New Books. 
Philosophical Transactions of the Royal Soctety of ait: jor 
the Year 1818. Part f. 
Tar Transactions of the Royal Society since the commencement 
of the present year have been distinguished by several papers of 
great novelty and importance. The original and valuable ex- 
periments of Captain Kater on the pendulum, for which the 
Copleian medal was adjudged to him, are at the present moment 
particularly deserving general attention. We regret that the 
Jate period of the month at which this part of the Society’s 
Transactions has appeared, obliges us to postpone till our next 
number, laying the particulars of these experiments before our 
readers. The following passage will show the general principle 
on which they have proceeded : 
“ Not feeling at all satisfied with the prospect which the use 
of a rod presented, I endeavoured to discover some property of 
the pendulum of which I might avail myself with greater pro- 
‘bability of success; and I was so fortunate as to perceive one, 
‘which promised an unexceptionable result. It is known that 
the centres of suspension and oscillation are reciprocal ; or, in 
other words, that if a body be suspended by its centre of oscilla- 
tion, its former point of suspension becomes the centre of oscil- 
lation, and the ‘vibrations in both positions will be performed in 
equal times. Now, the distance of the centre of oscillation from 
the point of suspension depending on the figure of the body em- 
ployed, if the arrangement of its particles be changed, the place 
of the centre of oscillation will also suffer a change. Suppose 
then a body to be furnished with a point of suspension, and 
another point on which it may vibrate, to be fixed as nearly as 
can be estimated in the centre of oscillation, and in a line with 
the point of suspension and centre of gravity. If the vibrations 
in each position’should not be equal in equal times, they may 
' readily 
