546 Prof. O. Reynolds on the 



heard nothing, either here or three quarters of a mile nearer. We 

 steamed out to 4| miles, when the sounds were for a moment faintly 

 heard, but they fell away as we waited ; and though the greatest quiet- 

 ness reigned on board, and though the sea was without a ripple, we could 

 hear nothing. "We could plainly see the steam-puffs which announced 

 the beginning and the end of a series of trumpet-blasts, but the blasts 

 themselves were quite inaudible. 



" It was now 4 P.M., and my intention at first was to halt at this dis- 

 tance, which was beyond the sound-range, but not far beyond it, and see 

 whether the lowering of the sun would not restore the power of the 

 atmosphere to transmit the sound. But after waiting a little, the an- 

 choring of a boat was suggested ; and though loth to lose the anticipated 

 revival of the sounds myself, I agreed to this arrangement. Two men 

 were placed in the boat, and requested to give all attention, so as to hear 

 the sound if possible. "With perfect stillness around them, they heard 

 nothing. They were then instructed to hoist a signal if they should hear 

 the sounds, and to keep it hoisted as long as the sounds continued. 



" At 4.45 we quitted them and steamed towards the South Sand Head 

 light-ship. Precisely fifteen minutes after we had separated from them 

 the flag was hoisted. The sound, as anticipated, had at length succeeded 

 in piercing the body of air be'tween the boat and the shore. 



" On returning to our anchored boat, we learned that when the flag was 

 hoisted the horn-sounds were heard, that they were succeeded after a 

 little time by the whistle-sounds, and that both increased in intensity as 

 the evening advanced. On our arrival of course we heard the sounds 

 ourselves. 



" The conjectured explanation of the stoppage of the sounds appeared 

 to be thus reduced to demonstration ; but we pushed the proof still 

 further by steaming further out. At 5| miles we halted and heard the 

 sounds. At 6 miles we heard them distinctly, but so feebly that we 

 thought we had reached the limit of the sound-range ; but while we 

 waited the sound rose in power. "We steamed to the Varne buoy, which 

 is 7| miles from the signal-station, and heard the sounds there better 

 than at 6 miles distance. 



" Steaming on to the Varne light-ship, which is situated at the other end 

 of the Yarne shoal, we hailed the master, and were informed by him that 

 up to 5 P.M. nothing had been heard. At that hour the sounds began to 

 be audible. He described one of them as * very gross, resembling the 

 bellowing of a bull,' which very accurately characterizes the sound of the 

 large American steam-whistle. At the Varne light-ship, therefore, the 

 sounds had been heard towards the close of the day, though it is 12| 

 miles from the signal-station." 



Here we see that the very conditions which actually diminished the range 

 of the sound were precisely those which would cause the greatest lifting 

 of the waves. And it may be noticed that these facts were observed and 



