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On the Vdodtij of Soimd. In a Letter from G. Von Moll, 

 F. R. S., Professor of Natural Philosophy in the University 

 of Utrecht, to Professor Jameson. 

 Sir, 



I Number for October of your valuable Journal, Mr H. 



Meikle notices the observations on velocity of sound, which were 

 made by Mr Van Beek and myself, and an account of which 

 was published in the Philosophical Transactions of 1824. Mr 

 Meikle very justly states his apprehension that some of these 

 observations are erroneously mentioned, as having been made in 

 January instead of June. 



On receiving your Journal, I immediately turned to the 

 Transactions, and found, to my no small mortification, that 

 Mr Meikle is perfectly correct. The error which he points out 

 really exists in the Transactions, by whose fault I am unable to 

 tell. Whether I, or the printer, is guilty, is impossible for me 

 to investigate. If the fault lies with me, I cannot plead in ex- 

 cuse the cause which Mr Meikle kindly suggests. It cannot 

 have arisen out of ignorance of the language, since Ju7iy and 

 January belong alike to both idioms. It is therefore a blunder ; 

 and I must request you to correct the effect of it as much as 

 possible, by informing both Mr Meikle and the public, that all 

 the experiments alluded to were made in June^ and none in 

 January. 



If I were in possession of the apparatus pointed out by your 

 able correspondent, I should be very anxious to try its efficiency ; 

 and if Mr Meikle has had one made, I should be very much 

 obliged to that gentleman for the information where a similar 

 one could be procured. I am, &c. 



G. Moll, F. R. S., 

 Utrecht, Professor of Natural Philosophy in 



2Qth February 1828. the University of Utrecht. 



Mr Meikle apprehends that the cause why the interval was 

 lopger in the experiments of 25th June, than the mean of both 

 directions on the 27th and 28th, must lie in the difference of the 

 guns, or of the mode of charging and firing them. In turning 

 to the diary of these observations, I find that the 25th, 27th, 



