520 



EESEAKCHES IN SOUND. 



about five miles per liour at the surface, and a greater velocity at the 

 height of the tower. Barometer, 30.25 ins. ; thermometer, 72°. 



Fi-. 4. 



BLOCK ISLAND 



t, S Buoy 



i^ 



■j^ 



i 





>^- 



^ O 



Scale of m ties 



i % 3 



