SUBMARINE SIGNALING BLAKE. 213 



REPORT OF CAPT. J. H. QUINAN, OF THE TT. S. REVENUE CUTTER " MIAMI," 

 ON THE ECHO FRINGE METHOD OF DETECTING ICEBERGS AND TAKING 

 CONTINUOUS SOUNDINGS.^ 



" We stopped near the largest berg and by range finder and sextant 

 computed it to be 450 feet long and 130 feet high. Although we had 

 gotten within 150 yards of the perpendicular face of this berg and 

 obtained no echo from the steam whistle, Prof. Fessenden and Mr. 

 Blake, representatives of the Submarine Signal Co., obtained satis- 

 factory results wdth the submarine electric oscillator placed 10 feet 

 below surface, getting distinct echoes from the berg at various dis- 

 tances, from one-half mile to 2^ miles. These echoes were not only 

 heard through the receivers of the oscillator in the wireless room 

 but were plainly heard by the officers in the wardroom and engine 

 room storeroom below the water line. Sound is said to travel at 

 the rate of 4,400 feet per second under water. The distance of the 

 ship, as shown by the echoes with stop watch, corresponded with the 

 distance of the ship as determined by range finder. On account of 

 the great velocity of sound through water, it was our intention to try 

 the oscillator at a greater distance for even better results, but a thick 

 snowstorm drove us into shelter on the Banks again. 



" On the morning of April 27 anchored in 31 fathoms of water with 

 75 fathoms of chain in order to make current observations. * * * 

 Prof. Fessenden also took advantage of the smooth sea to further 

 experiment with his oscillator in determining by echo the depth of 

 water, the result giving 36 fathoms, which seemed to me very close." 



iFrom the Hydrographic Office Bulletin of May 13, 1914. 



