36 Scientific Proceedings, Royal Dublin Society. 
The action is as follows :— 
Every second the lever with the V tooth is brought sharply 
down on the wheel a,a. If all be right, this should occur just as 
the V cut is directly under the tooth, and the spring contacts s, s, 
are in such a position that they do not make contact with either 
of the brass bands 8, 8, 6’, 0’. 
So long as the clock is going correctly, the lever with its 
V tooth will hit accurately into each V groove; and no connection 
will take place. If, however, the clock has gained or lost so much 
as the thirtieth part of a second, the V tooth will not strike 
accurately into the V cut, but will hit one side before the other, 
and consequently will slightly displace this wheel on the shaft (it 
being only carried by friction) ; and this will immediately bring 
into action the accelerator or retarder as may be required, and the 
correction will be repeated at the next stroke, if the error be not 
completely wiped out. 
When the correction is perfectly made, the wheel will be 
brought back to its normal position by the action of the V tooth. 
This arrangement has been found to give as great accuracy as 
the original form ; and it has the advantage of greater simplicity. 
