542 Icebergs and their Location, in Navigation. [May 31, 



to determine. In general, it may be said that an iceberg will make 

 itself felt in the first place by a rapid rise of temperature as it is 

 approached. In the immediate vicinity of the ])erg the temperature 

 falls quickly. The first warning will be when the temperature begins 

 to mount up the scale above the surrounding sea temperature. In 

 regions where icebergs are in close proximity, safe navigation will be 

 found possible, since no isothermal line can lead to an iceberg. 



In conclusion, I wish to impress upon the reader the importance 

 of the fact that the actual temperature of the water in the ice track 

 is no guide to the proximity of even the largest iceberg. The expe- 

 riences of North Atlantic sea captains alone testifies to the uselessness 

 of individual observations. It is to the small variations of tempera- 

 ture we must look for the infallible guide, and by means of the 

 character of these variations we can determine the presence of ice, 

 land, or currents. 



[H. T.B.] 



