• OMPUTATIOlf OF SQUARES AND CUBES. 



of profecuting the inquiry, fuch as (he rarely affords to perfona 

 of corredl obfervation. I will not trefpafs upon your pages 

 by a comment on the remaining fafts of my friend's letter ; 

 let them fpeak for themfelvesj in particular, the preference 

 of a thunder cloud to low ground, in the prefence of lofty 

 objefts, including a tall tree. 



JOHN GOUGH. 



ANNOTATIONT. 



I BELIEVE the opinion that fairy-rings are caufed by light- 

 ning, is of confiderable antiquity. Dr. Prieftley gave fupport 

 to this conclufion by his experiment of the concentric rings 

 formed on a polifhed metallic furface by the explolion of a 

 battery. An effefl of this kind produced in Kenfington Gar- 

 dens, is defcribed, with an engraving, in our Quarto Series, 

 Vol. I. p. 546. 



W.N. 



On the Computaiioh of TaHles of Squares and Cubes, In a Letter 

 from E. O. 



To Mr. NICHOLSON. 

 SIR, 



Computation of 1 SHOULD not have troubled you with any remarks on the 

 fquares and method of computing fquares and cubes, if I had not feen the 

 paper which was printed on that fubjed in your Journal for 

 laft July. But as it appears, from that letter, that there may 

 be perfons who would like to employ themfelves on thefe cal- 

 culations, it is defirable that the plainefl and eafieft methods 

 fhould be pointed out to them. 



Every one who is accufioraed to calculation, is acquainted 

 with the advantage of eonftantly repeating (he fame opera- 

 tions. When the refult of any calculation is to be made out, 

 in fome parts by multiplication and in others by divifion, fub- 

 tra£tion, or addition, it is impoffible for the moft unwearied 

 diligence to avoid occafional miftakes. It is right, therefore, 

 to iiroplify as much as poffible in this refped; and if the calcu- 

 lation 



