﻿fyc.for Pare Notes of different Pitch, 



253 



single experiment taken at random from my journal. Thi.s 

 was one of a series made at the beginning of the inquiry, 



when I had joined two tnhcs together in order to follow the 

 maxima as far down into the tube as possible. As was to bo 

 expected on account of the decreasing intensity, the readings 

 became more dirfieult the farther they were removed from the 

 source of sound. After convincing myself in this way that 

 the wave-length remained constant, I determined only the 

 uppermost maximum and the lowermost that could be distinctly 

 observed, divided their difference by the number of half wave- 

 lengths contained in the interval passed through, and arrived 

 in this way at the mean half wave-length. 



Fork c lh n . . ■ 

 Tube II., diameter 

 Mean temperature 

 Vapour-tension 



Barometric height 



= 512. 



= 17-1 millim. 

 = 12°-3C. 

 = 10*5 millim. 

 = 754 millim. 



Readings for the Maxima, 



Temp. 

 (J. 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



12 



millim. 

 1.37 



millim. 

 483 



millim. 

 811 



millim. 

 1136 



millim. 



14G4 



millim. 

 1792 



millim. 

 2122 



12-3 



157 



4S4 



812 



1138 



14GG 



1793 



2119 



12-3 



156 o 



484 



811 



1139 



1400 



1792 



2121 



127 



1575 



485 

 484 



812 

 8115 



1140 



1467 



1791 



2121 

 21207 



Mean 123 



157* 



1137-7 



14U0-3 



1792-7 



f Wave-lengths. 



Velocity. 



327 millim. 



320-3 metre 



3275 „ 



321 i-9 „ 



326-2 „ 



3250 „ 



328-0 „ 



327-8 „ 



3264 „ 



325 8 „ 



328 



3274 „ 



Menu .... 



3200 ., 



* The first quarter wave-length in the above experiment, increased by 

 Rayleigh's correction (157+0*82 radius), gives a velocity of 827*4 metre. 

 1 very often calculated the velocity iu this way, and always found nearly 

 the same value as from the other readings. Such values were, however, 

 never included in the mean 



