1821.] On Capt, Katers Experiments on the Pendulum, 387 



brought against me of not obtaining better information before I 

 estimated the price of gas at what I did in my former paper, may 

 certainly be retorted upon him, for not having made his state- 

 ments more correct than he has done. I am, however, indebted 

 to him for affording me an opportunity, not only of confirming 

 my former statement, but of showing that, instead of exaggerat- 

 ing the superiority of oil gas in point of economy, I have under- 

 rated it, and that its advantages are much greater than I had 

 myself conceived before I entered into this more complete inves- 

 tigation. Had it been practicable, it would not have been 

 uninteresting to have shown what dividends are paid by the 

 above enumerated Companies ; how many pay lOs. per cent. ; 

 how many pay more ; how many pay less ; and how many pay 

 none at all. 



I am, yours, &c. M. Ricardo. 



March 23, 1821. 



Article XI. 



Remarks on Capt, Kater^s E.rperimenls on the hength of the 



Pendulum. 



(To the Editor of the Annals of Philosophy.) 



SIR, 



As notices of Capt. Kater's experiments on the length of the 

 pendulum have occasionally appeared in your journal, the fol- 

 lowing remarks relative to that subject may, perhaps, be allowed 

 a place in it. I am, &c. &c. X. 



An article appeared in the Edinburgh Review for November, 

 1820, giving an account of Capt. Kater's experiments for deter- 

 mining the length of the pendulum at different stations in Great 

 •Britain ; and the writer has made some observations which seem 

 to be founded in an erroneous view of some of Capt. Kater's 

 "Statements. At p. 343, the following passage occurs : 



" Capt. Kater seems to have mistaken the import of Dr. 

 Young's statement, when he uses this correction for the attrac- 

 tion of the ' elevated part interposed between the general surface 

 and the place of observation, nothing being said of lateral 

 attraction caused by surrounding matter. But Capt. K. appUes 

 the correction for the error produced by hills lying round the 

 pouit of observation." 



On this passage I have to remark, that Capt. Kater does not 

 apply the correction for the error produced by hills lying round 

 the point of observation. Indeed the only proof which this 

 writer brings to support his charge is, that Capt. K. says, " th« 



2 B 2 



