W. B. Taylor— Recent Researches in Sound. 



•y to be caused by a reflection of the sound from the crests 



slopes of the waves. 



L] On September 23rd, 1874, three observations were made 



pposite directions about ( 



a half miles from Sandy Hook, New Jersey. First, before 

 noon with the wind from the west, second, at noon with the 

 wind lulled to a calm, and third, an hour and a half later, with 

 the wind blowing from the east. These observations gave the 

 unexpected result of the sound being heard in each case uni- 

 formly farthest from the west, irrespective of the wind. (p. 

 114.) On the next day, September 24th, the observations were 

 repeated farther out at sea, or six miles from the nearest land. 

 Small balloons, sent off with each observation on the sound, 

 showed that notwithstanding the change of surface wind as be- 

 fore, from morning to afternoon, the upper current of wind was 

 steadily and continuously from the west. (p. 115.) Professor 

 Henry supposes that in the first case " the motion of the air 

 being in the same direction both below and above, but proba- 

 bly more rapid above than below on account of resistance, the 

 upper part of the sound-wave would move more rapidly than 

 the lower, and the wave would be deflected downward, and 

 therefore the sound as usual heard farther with the wind than 

 against it." In the third case with a local sea-breeze in the op- 

 posite direction, and the upper current remaining unchanged, 

 " the sound should be heard still farther in the same direction 

 or against the wind at the surface, since in this case the sound- 

 wave being more retarded near the surface, would be tipped 

 over more above, and the sound thus thrown down." (p. 115.) 

 This explanation derived from a communication of Professor 

 Stokes, at the Dublin Meeting of the British Association in 

 1857, (Kep. of B. A., 1856, p. 22 of Abstracts) would appear 

 to be a very satisfactory solution of the apparent anomaly. 



II. 



gineer in charge < 



Hamp 



In 1870, General Duane, the engineer in charge < 

 house District embracing the coast of Maine, New 

 and Massachusetts, was assigned by the Light House Uoara, 

 (as one " who from his established reputation for ingenuity and 

 practical skill in mechanism, was well qualified for the work,") 

 to make experiments and observations on fog-signals. Accord- 

 ingly during the year 1871, extensive investigations were made 

 by him at Portland, Maine. Passing over his valuable remarks 

 on the qualities of fog-signals, the following are the principal 

 facts observed by him : 



[A.] The extremely variable range of sound. The steam fog- 

 whistles on the coast of Maine could frequently be heard at a 

 distance of twenty miles, and as frequently could not be heard 



