new standards of weights and measures. 5 



the clock, this constant difference of the number of vibrations 

 from the truth will not affect the ultimate deductions. As 

 the most direct method of removing any doubts which may 

 be entertained upon this subject, I shall add a comparative 

 Table of the successive differences of the number of vibra- 

 tions in twenty-four hours, which I have computed from the 

 whole of Captain Sabine's observations, by employing the 

 disappearances only, of the disk. 



As the comparative results, by the method of disappear- 

 ances, would to a certain degree be vitiated by the use of a 

 disk of a different size, the observations made in London in 

 1824 with a silver disk are omitted. 



The differences of the results being so minute, and the 

 mean of the whole being absolutely nothing, the conclusion 

 i& warranted that the method of observing coincidences by 



