88 



THE NATIONAL GEOGRAPHIC MAGAZINE 



AMERICAN BLUEJACKETS ADJUSTING THE DELICATE MECHANISM WHICH CHANGES 



A MINE FROM A HARMLESS, INSENSATE BALE OE STEEL TO CONCENTRATED 



CATACLYSM EOR ANYTHING WHICH TOUCHES IT 



effective barrier that could be maintained 

 against attempts to break through (see 

 maps on pages 86 and 109). 



If mines of previous types were used 

 their number was prohibitive, impossible 

 to manufacture or provide with explosive 

 within two years, under existing condi- 

 tions, not to mention the task of planting ; 

 but the new American mine would do 

 more than twice what the others could, 

 and the joining of our mining forces with 

 the British would more than double the 

 means available. 



From the outset, the operation was 

 seen to be of great magnitude, with a 

 mass of detail requiring constant fore- 

 sight and careful adjustment. Besides 

 the bigness, other features promised great 

 difficulty, such as deep water, 300 to 900 

 feet, danger to the mine-layers from their 

 own mine fields in bad weather and fog, 

 and inexperience of the large proportion 

 of new personnel. 



Fortunately, our Navy had been de- 

 veloping a mining force for nearly three 



years. It was small but well trained, and 

 it looked upon difficulties only as things 

 to be overcome. On the strength of its 

 own experience, this force was confident 

 that the large operation could be accom- 

 plished. 



Likewise, the British, with their three 

 years' experience in the war and knowl- 

 edge of North Sea weather, felt sure it 

 could be done. 



Difficult in many ways, seen and also 

 unseen — venturesome, arduous, and very 

 hazardous — it was all of these beyond any 

 doubt ; yet, if only half successful, the 

 operation would go far toward beating 

 the submarines, and it could be done. So 

 it was undertaken. From the President 

 down, every one in authority was strong 

 for it. 



the order: "go ahead" 



All these preliminaries take time, and 

 the new invention itself had to be put 

 through severe trials before we could feel 

 sure enough ; but by the end of October, 



