Records of the Free Vibrations of a Tuning-fork. 451 
~~ 
The specimen records illustrate the character of the autograph. 
The record A is that of the experiments 2 and 8 of the second 
series. The dots in the middle row represent the siren revolu- 
tion, the heavy dashes on one side of them the beats, and the 
light dots on the other side the seconds. It will be observed 
that the first two seconds of the record were useless for want 
of a coincidence. The first coincidence occurs at the mark. |, a 
second one similarly marked occurs three seconds later, a third 
five seconds after the first, a fourth at the end of ten 
and 
seconds. Kixperiment No. 2 of the table gives the results 
recorded in the interval between the third and eighth seconds, 
and experiment No. 8 is the result of the w hole ten seconds. 
The “ marginal remark” on the original bent is “ coincidences 
not quite perfec t, but errors similar and equal.” 
es record B is a ected o “lapse Ci of October 20. 
will be seen that the ies: second’s dot does not quite coincide 
with the siren record, though the nearest siren dash is partly 
effaced. If this were taken as a coincidence, the result would 
of 
1884—14 : 
4 = 38415 showing how the accuracy 
be much 
