DERELICTS AND ICEBERGS 43 



released the cargo, and to make sure that the 

 stubborn wreck would sink, the San Francisco 

 fired several shells into her stern, scattering 

 the fragments of the once-staunch schooner far 

 and wide. 



Only by such methods can the ocean lanes 

 be kept free from floating wrecks, and even 

 with all our efforts a great many vessels strike 

 derelicts and are injured every year. There 

 are so many wrecks floating about, — as many 

 as one thousand having been reported in one 

 year from the North Atlantic alone, — that it 

 is almost impossible to hunt down and destroy 

 them all, but fortunately they do not all stay 

 afloat or drift about for very long. It is esti- 

 mated that the average length of time which 

 a derelict remains afloat is one month, and 

 as an average of about nineteen wrecks are 

 reported monthly, there must be about nine- 

 teen wrecks constantly afloat in the North 

 Atlantic. The majority of the derelicts are 

 seen in the Gulf Stream off our Atlantic coast, 

 north of 30° north latitude and west of 60° 

 west longitude, and thus in the track of a great 

 deal of navigation. That they are a serious 



