408 WAIDNER, DICKINSON AND CROWE : OCEAN TEMPERATURES 



in sea water. The following determinations of the densities of 

 samples of sea water, taken under conditions specified and after- 

 wards tested in the laboratories, serve to illustrate this. 



Echoes from icebergs. The testimony of numerous observers 

 is on evidence that the echo of the fog horn may frequentlj^ but 

 by no means always, be detected when in the proximity of an 

 iceberg or even of a bank of fog. The amount of evidence on 

 this point leaves no doubt as to the correctness of the above 

 statement. The experiment of sounding the fog horn when in 

 the vicinity of a number of the bergs encountered on thetrip was 

 tried but in lio instance was an echo detected. A few experiments 

 were also made to determine whether an echo could be detected 

 under water coming from the larger submerged portion of the 

 berg. For this purpose the ship's bell was lowered into the water 

 and signals produced by striking the bell. Observers stationed 

 at the ship's submarine signal telephones listened for evidences 

 of the echo. The ship was at a distance of 1 to 2 miles from the 

 fair sized berg encountered by the U.S.S. Chester on the afternoon 

 of June 17. It was difficult to draw postive conclusions on ac- 

 count of the disturbing noises present in the telephone receiver, 

 but a number of observers were convinced that they heard faint 

 echoes. There was no time to investigate and improve the tele- 

 phonic apparatus, so that the most that can be said is that these 

 preliminary experiments look hopeful enough to merit more 

 careful experiments. 



Other ohservations. The results of other experiments such as 

 firing 3 and 5-inch shells into the berg, the utility of searchlights 

 in locating bergs at night, etc., will undoubtedly be covered in 

 the official reports of the commanding officers. It may be worth 



