( 448 ) 



will be small compared to that of the forresponding pendulum. For 

 such a motion A"i jt^ -{- K, rr.^ remaining in the end, the two clocks 

 will each have their own rate ") whilst however slight periodic 

 variations in their amplitudes are noticed, caused by the cooperation 

 of the two remaining principal oscillations whose periods differ con- 

 siderably if /i and /.^ are sufficiently unequal. 



11. Let us now however suppose that 1^ and 4, differing at first 

 considerably, are made to correspond more and more, for instance 

 by displacement of the pendulum weights. The chief consequence will 

 have to be that, according to equation (15), the amplitudes of both 

 pendulums will become more and more comparable to each other, 

 for /v^rri as well as for K^cr.^, in consequence of which to obtain 

 their motion for the compound oscillation K^:n;^ -\- K.^sr^ we shall 

 finally have to compose for each of them two oscillations with com- 

 parable amplitudes, and whose periods of oscillation differ but slightly. 

 As is known this leads for both pendulums alternately, to periods 

 of relatively greater and smaller activity, i. o. w. to the phenomenon 

 of transference of energy of motion from one pendulum to another 

 and back again; the period in which this alternation of activity 

 takes place will be the longer according as /^ and /^ differ 

 less '). 



2^Io\v however a suchlike behaviour of the two pendulums accord- 

 ing as it gets more and more upon the foreground when /^ and ^ 

 approach each other, becomes less and less compatible with the regular 

 action of the two clockworks. For, during the period of smaller actixity 

 of one of the pendulums the motive work corresponding to it will 

 finally, when the remaining activity has become much smaller than 

 the normal, come to a stop. Then one of the two will take place : 

 either the principal oscillation which is sustained particularly by this 

 work is powerful enough to keep on till the period of greater acti- 

 vity has been entered upon, and this will be deferred the longer 

 according as /j and 1^ differ less, or it is not so. In the first case 

 the clock can keep going with alternate periods in which it ticks and 

 in which it does not tick, which phenomenon may of course present 



1) Both rates however a little more rapid than for independent position. 



~) These phenomena remind us of what Ellicott observed later on (see note (4) 

 p. 438). However the correspondence is not complete, as in the case treated here 

 both clocks retain their different rate, whilst Ellicott mentions emphatically that 

 the two clocli.s did not differ a second for many days. We shall therefore have 

 to again refer to these observations at case C. 



