418 Dr. R. Konig on the Simultaneous 



simply powerful tuning-forks, whose intensity of tone required 

 no further reinforcement. 



The whole series of tuning-forks and sounding-boxes which 

 I made use of for these experiments was as follows : — 



1. Five tuning-forks which without weights gave the notes 

 double Gr, C, E, Gr, e (sol_!, do 1? mi l5 solj, do 2 ). Each of the 

 four higher forks can, by means of its sliding weights, be 

 tuned down to the note of the next deeper fork. The double- 

 G fork can be lowered by a couple of sliding weights to 

 double E, and by another couple as far as to double C 

 (do_! = 64 v. s.); and this latter limit may still be exceeded by 

 increasing the weights upon the slides. The positions of the 

 sliding weights upon these forks are marked at intervals of 

 single vibration for the octave from double C to C, and by 

 doable vibration for the next higher octave. 



The prongs of the lowest fork are 35 millims. in thickness, 

 55 millims. in breadth, and about 75 centims. in length. The 

 prongs of the other four forks are 39 millims. thick, 55 millims. 

 broad, and their length varies from about 70 centims. to 

 49 centims. These five forks, without their stands and sliding 

 weights, weigh 130 kilogrammes. 



2. Eight tuning-forks, which without weights are tuned to the 

 notes c, e,g, c, c', e f ,g f , c" (do 2 , mi 2 , sol 2 , do 3 , do 3 , mi 3 , sol 3 , do 4 ), 

 and by means of their sliding weights are capable of producing 

 all the intermediate notes also. Their prongs are 26 millims. 

 thick, 26 millims. broad, and from about 59 to 19 centims. 

 long. 



The tuning-forks for the octave from c to c' have a division 

 for placing the sliding weights at from two to two double 

 vibrations, and for the next higher octave from four to four. 



3. Nine forks tuned to the scale of c" to c f,/ , and to the 

 seventh harmonic of the small c, of which the prongs are 

 25 millims. broad, 25 millims. thick below, and diminish to 

 about 12 millims. less at the ends. Their length varies from 

 about 20 to 13 centims. 



4. Twelve tuning-forks for the notes of the scale from c 

 to c IV , the eleventh, thirteenth, and fourteenth harmonics of c, 

 and the note of 2389'3 v. s., which forms with c' (512 v. s.) 

 the ratio of 3 : 14, with prongs 15 millims. in breadth, 10 millims 

 in thickness below, and about 7 millims. at the ends, and from 

 about 9 centims. to 6 centims. in length. 



5. Eleven forks for the notes of the scale from c iy to c v , and 

 the eleventh, thirteenth, and fourteenth harmonics of c' '. The 

 breadth of the prongs is 23 millims., the thickness below 

 18 millims., and at the ends about 9 millims. Their length 

 varies from about 8 to 5 centims. 



in 



