On tJis Velocity ofScmnd. 81 



garding the precise effect which moisture really exerts on sound 

 at any temperature, there being no such thing as making expe- 

 riments on sound in perfectly dry air. 



The value of the experiments made during the Arctic expe- 

 ditions, will be better appreciated while we consider the number 

 and magnitude of the discouragements under Which they were 

 achieved. They cannot, it is true, be said in every respect to 

 equal the researches which have been prosecuted on a more ex- 

 tended scale, in temperate regions ; but still the results are inte- 

 resting, as affording farther evidence of the insufficiency of the 

 most refined theories hitherto proposed. 



The following Table is a summary of the results obtained at 

 Port Bowen, by Captain Parry and Lieutenant Foster, by means 

 of a brass six-pounder, over a range of 12892.89 feet. The 

 sound came in the direction of S. IV 48' E. 



Data 



Wind. 



Inches. 



Tempera- 

 ture Fah- 

 renheit. 



Intervals Elapsed. 



Parry. 



Foster. 



Mean. 



Velocity 

 per Second 

 in Feet. 



1824. 



Nov. 24. 



Dec. 8. 



1825. 



Jan. 10. 



Feb. 7. 



17. 



21. 



Mar. 2. 



22. 



June 3. 



4. 



ESE, 



N, NE 



ESE, 



NE 



easterly^ 



westerly, 



easterly, 



SE. 



light, 

 squally, 



light, 

 light, 

 calm, 

 calm, 

 light, 

 light, 

 light, 

 strong, 



29.841 

 29.561 



30.268 

 29.647 

 29.598 

 29.735 

 30.398 

 30.258 

 30.118 

 30.102 



— r 



^ 9 



37 



24.5 



18 



37.5 



38.5 



21.5 



33.5 



35 



12.3525 

 12.331 



12.5889 



12.639 



12.372 



12.8167 



12.64 



12.4 



11.7333 



11.5889 



12.43 

 12.5266 



12.47 



12.6167 



12.44 



12.7067 



12.78 



I2.7I67 



11.744 



11.4733 



12.3912 

 12.4288 



12.529 



12.6278 



12.406 



12.7617 



12.71 



12.5583 



11.7387 



11.5311 



1040.49 

 1037.34 



1029.01 

 1020.99 

 1039.25 

 1010.28 

 1014.39 

 1026.64 

 1098.32 

 lll&lO 



Omitting the last of these results on account of the strong 

 wind, the mean of the other nine give a velocity of 1035.19 feet, 

 at the temperature of — 17.72 F. Substituting this tempera- 

 ture in the formula given above, and omitting P because y is 

 wanting or unknown, we obtain a velocity of 1001.92 feet, which 

 comes short <rf experiment by 33.27 feet ; a difference which can' 

 nevet" be owing to errors of observation, but more likely to the' 

 great intensity of sound in air condensed by cold. 



Lieutenant E. N. Kendall,- who accbmpanied Captain Frahfo- 

 lin in his second journey to the shores of the Polar Seff, made 

 numerous experirflents on sound at Fort Franklin, by means of 

 muskets. The ranges were from 1521 to 6084 feet ; and, gene- 

 rally, shots were fired at both ends of the base, with the view of 



