78 



Lord Rayleigh on 



[May 15, 



Here again we observe the tendency of the wave-length to increase 

 more rapidly than the square root of the pressure. 



At higher pressures the difference is naturally still more marked. 

 With the same aperture, and the wooden box as reservoir, the results 

 were : — 



Pressure. 



1072 



992 

 888 

 827 

 762 

 702 

 619 

 539 

 468 

 415 

 337 

 292 

 251 

 213 



189 

 163 

 140 

 111 



90 

 70 

 57 

 45 



Table VI. — December 17. 

 Wave-length. 



\/ (Pressure), 



102 



94 



89 



86 



81 



77 



70 



66 



59J 



541 



47 



42 



381 



341 



33 



31 



28i 



24f 



22J 



19f 



m 



161 



80 

 77 

 73 

 70 

 67 

 65 

 61 

 57 

 53 

 50 

 44 

 42 

 38 

 35 



33 

 31 

 29 

 25 

 23 

 20 

 18 

 16 



The wave-lengths down to 34J are immediate measurements ; those 

 below are deduced from measurements of two wave-lengths. 



Similar experiments were made with jets from a square hole (side = 

 2 millims.), the peculiarities of which are repeated four times in pass- 

 ing round the circumference. Two wave-lengths were measured. 



Table VII.— December 14. 



Pressure. 



447 

 377 

 312 

 269 

 247 

 218 



Wave-length. 

 32 

 291 



a/ (Pressure). 



30 -2 



27 

 241 

 23 

 2H 



27 

 25 

 23 

 22 

 21 



Corrected. 

 29 -9 

 27-4 

 24 -9 

 23 1 

 22 -1 

 20 7 



