386 ^« 'unproved Piano Forte, — New Logarithmetk Scales. 



entirely: whereas the extraordinary image continues to be trans- 

 mitted, without undergoing any other diminution of density than 

 that which arises from absorption. 



This property gives birth to several other phsenomena, which 

 it is easy to foresee when we know them, and which experience 

 also confirms. They have a considerable analogy with those 

 which Dr. Brewster discovered in agate. On examining the lat- 

 ter, M. Biot was convinced that they do not take place, as in the 

 tourmaline, but beyond certain limits of thickness ; for, by thin- 

 ning the agate sufficiently, all the properties are restored to it 

 which belong to crystals endowed with double refraction. 

 [To be continued.] 



LXIX. Intelligence and Miscellaneous Articles. 



AN riMPROVED PIANO FORTE. NEW LOGARITHMETIC SCALES.— 



QUANTITY OF RAIN ON BLACKSTONB EDGE. 



Mr. Editor, — xIappening to have known that Mr. Loescli- 

 vian the musical-instrument maker has been long employed, un- 

 der the direction of Earl Stanhope, in constructing a new in- 

 strument, and having heard that it was at length completed, I 

 called yesterday at his house in Newman Street, and was highly 

 gratified by examining and hearing the novel and powerful ef- 

 fects of the single steel strings of his Lordship's invention : by 

 which every desirable degree of loudness, more indeed than many 

 would like in a small room, combined with a mellow sweetness 

 of tone, seems accomplished, and the effect of an improved 

 swell thereon, is excellent. The lower of his Lordship's Strings, 

 or Wires rather, seem near or quite a tenth of an inch in dia- 

 7neter, and more resemble musical bars than strings, in their 

 tone and effect. The chief difficulties have, as 1 understand, 

 lain in effecting a construction of the Instrument, to bear with- 

 out alteration of form, so vast a strain as these strings collectively 

 require, and to preserve at the same time its resonant effect ; 

 and in the construction of the hammers, for duly impelling these 

 massive strings, without too audible a blow, and rendering the 

 toiich too heavy. 



With respect to its mode of tuning, it will I trust, to all com- 

 petent judges of the subject, be a recommendation, and credi- 

 table also to his Lordship as a philosopher, to mention, that 

 " Bi-equal Thirds," or " Tri-equal Quints," &c. have not been 

 attempted to be introduced on this new Instrument ; but Mr. 

 Loescliman lias been left to apply his great practical tuning skill, 

 in doing the best that seems yet to have been effected on stringed 



Instrunjents 



