Icebergs 



iceberg is colder than the surrounding water, it will certainly 

 sink, and its place be taken by other water which has not 

 been chilled. It will, therefore, be seen that the testing of 

 the water at any considerable distance from an iceberg can 

 be of little or no use. 



With the air, however, it is quite different. The ice- 

 berg is never moving as relates to the water, it is always 

 travelling with the water and at the same speed, but the 

 air is always travelling as relates to the iceberg. The result 

 is that a very large quantity of air is chilled by passing 

 over the iceberg, and this forms a bank of air at the lee- 

 ward of a greater density than the surrounding air, and this 

 of itself is capable of reflecting sound or the kind of vibrations 

 which I employ in my apparatus. 



I am very strongly of the opinion that the thermometer, 

 either in the air or in the water, can be of very little use, 

 whereas my apparatus not only detects the presence of an 

 iceberg, but it indicates its approximate direction from the 

 ship, and measures the distance with a high degree of 

 accuracy. Moreover, my apparatus lends itself admirably 

 for transmitting messages, providing the distance is not 

 greater than twenty miles. 



Suppose two ships, each provided with my apparatus, should 

 wish to communicate, it is only necessary that the recording 

 apparatus should be turned in the direction of the ship and 

 the mechanism allowed to feed out the strip of paper. We 

 should then be able to dispatch and receive messages, using 

 the Morse code a short blast for the dot and a long blast for 

 a dash. In like manner a ship would be able to communicate 

 with the shore, providing the distance was not too great. 



45 



