30 Reply to F.R.S.L.'s Remarks on Compound Interest. 



The metals used by me in the construction of the receiver 

 and conducting tubes, were, plate iron and tin, painted, to 

 prevent oxidation ; and they were found to last several years. 

 The above remarks are not intended to discourage im- 

 provements in such instruments, but to prevent an erroneous 

 impression upon your readers. 



I am, Gentlemen, 



Your obedient servant, 

 Leighton, Dec. 10, 1827. B. Bevan. 



[We think that Mr. Taylor's expressions can hardly be 

 considered as intending to propose his instrument to super- 

 sede Mr. Bevan' s, or to be an improvement upon it. 



He describes his object as indeed a different one, which 

 may suit others as well as himself, and which is simply to 

 have a rain-gauge which will record quantities between periods 

 of observation, — if the term registering be objected to, — and 

 without the care or management of persons skilled in such 

 matters. 



Mr. Taylor seems to us to acknowledge the merits of Mr. 

 Bevan' s instrument, and does not appear to have thought of 

 any rivalry between the two inventions. — Edit.] 



VIII. Reply to F.R.S. L.'s Remarks on Compound Interest. 



To the Editors of the Philosophical Magazine and Annals. 

 Gentlemen, 



YOUR correspondent F. R. S. L. in his " Remarks on the 

 Principle of Com pound Interest," seems to have bewildered 

 himself sadly in his attempt to defend Dr. Young's paper on 

 that subject ; nor is it in my power to extricate him out of the 

 labyrinth. " It is," he says, " lawful to receive ^%jl. each 

 day that 100/. is in the hands of the borrower, but at the end 

 of the year it is only lawful to receive 51. for the use of the 

 100/. without any interest on the interest." — All this is true 

 if the interest is payable yearly; but if it is made payable at 

 shorter intervals, what law restrains the lender from improving 

 that interest during each interval, like any other part of his 

 capital ? The borrower pays only at the rate of 51. per cent ; 

 nor does the lender improve his money at a higher rate, the 

 advantage in his favour arising only from the more frequent 

 opportunity of adding the interest to his capital. From the 

 nature of compound interest, it is evident that the value of an 

 annuity payable at shorter intervals than one year must vary 

 less and less from the value of the same annuity payable 



yearly, 



