Quantity of Rain on Blackstone Edge. — Astronomy. 387 



Instruments with only 1 2 sounds in the octave, and intended for 

 general playing, viz. making the major Thirds a little sharper • 

 than perfect, perhaps 1 or 2 i"s, and the Fifths, of course, 2| or 

 2| ^s* flatter than perfect, respectively. 



I beg to be permitted to mention here, that since I began in 

 1 807, to make new and more accurate reductions of Musical 

 Intervals /ryrw one notation to others, than had previously been 

 done, I have constantly used " Logometric Logarithms," that 

 is, I constructed a table of the logarithms of the logarithms of 

 musical ratios, and have long ago communicated the mode of 

 making and using these to my friends C.J. Smyth and others. 

 On the 17th of November last, a paper was read to the Royal 

 Society (and which is just now published in the Phil. Trans, of 

 1815, part i.) by Dr. Peter M. Roget, wherein this important 

 and perhaps hitherto mipublished application of logarithms is 

 described, and they are applied on straight, spiral and diagonal 

 Scales, to the most easy performing of numbers of the most la- 

 borious arithmetic operations by any other known means, in the 

 involution and extraction of Roots, compound Interest, experi- 

 mental Equations, Musical calculations, &c. &c. 



This curious and important paper, you will, I hope, at the pro- 

 per time, transfer to the pages of your useful Miscellany, and 

 thereby oblige yours, &c. 



May 13, 1815. ' JoHN FaREY, Sen. 



p.S. — I should feel very highly obliged to your Correspondent 

 Mr. Thomas Hanson of Manchester, who in your last number, 

 page 317, and in vol. xliii. page 237, has given an account of 

 Rain that fell on Blackstone Edge in the years 1814 and 1813, 

 respectively, to either explain the mistake committed in the first 

 of these accounts ; or otherwise, throw what light he may be 

 able, on such a most extraordinary difference, as 29070, and 

 86'0S5 inches, in the corresponding 9 months of these two fol- 

 lowing years ! ! : his remarks and promise in p. 239 of the former 

 account, embolden me to confidently expect his speedy answer 

 hereto. 



ANCIENT ASTRONORiY. 



Baron de Zach, in his publication on the Attraction of Moun- 

 tains, a valuable astronomical work lately published at Avignon, 

 in two volumes 8vo, after speaking of a Trigonometrical Survey 

 of the neighbourhood of Marseilles, and its utility in forming 

 a topographical Map gf the surrounding territory, proceeds thus : 



" This affair led U3 to examine several interesting points in 



• See Plate V, in vol. xxviii. and Cofbl. xviil. In p. 375 of vol. xxxvi. of 

 Phil. Mag. 



B b 2 this 



