A New System for Preventing Collisions at Sea 



the lights of passing ships. At about nine o'clock, after 

 sending out many blasts to port and starboard, and also 

 dead ahead, we have a very slight indication that there is 

 some large object ten miles distant, and very nearly in the 

 direction we are going. We expect to get a stronger reading 

 in a few minutes, but do not do so. However, we keep on 

 sending out blasts, and at the end of an hour the readings 

 are more distinct and the distance is reduced from ten miles 

 to seven, showing that the object in question is evidently a 

 ship going in the same direction as ourselves but at a lower 

 speed. We come up to her and pass her in a short time ; we 

 next find that there is a very large object off our starboard 

 beam. Our recorder shows the distance to be over twelve 

 miles, and still the markings are quite distinct. What can 

 it be ? Reason tells us that it is a big liner with her 

 immensely large broadside in a position to send back to us 

 an echo such as we have never received before at such a 

 distance. We continue sending out blasts, and soon find 

 that the big ship is going in the same direction as ourselves, 

 and at a speed of fully three miles an hour faster than our 

 own ship is travelling. In a short time she is so far ahead 

 of us that we cannot receive back an echo. 



The day following is very fine and cloudless ; the sun shines 

 down from a deep blue sky with remarkable intensity. There 

 is practically no wind. However, at about midday, the little 

 wavelets on the surface of the water show that the air is in 

 motion. Currents of cold air are descending, spreading out 

 over the surface of the water, and producing the little waves 

 that enable us to locate both the descending and ascending 

 currents. The warm air produced by the intense heat of the 



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