118 



THE NATIONAL GEOGRAPHIC MAGAZINE 



DUE TO AN ELECTRICAL PROTECTIVE DEVICE, THE LAPWING SUCCEEDED IN PASSING 



SAFELY OVER THIS MINE, WHICH EXPLODED AS SOON AS IT WAS OUTSIDE THE 



RADIUS OF IMMUNITY ESTABLISHED BY THAT REMARKABLE CONTRIVANCE 



Aside from shaking the vessel severely and breaking such articles as chinaware and lamp 

 globes, no damage was ordinarily incurred by an explosion so far astern. 



necessitated docking the sweepers to stop 

 the leaks caused by explosions. 



The rate of sweeping had been far be- 

 low our expectations, but we were learn- 

 ing. 



VAST QUANTITIES OF SWEEPING GEAR 

 BLOWN AWAY 



The most serious factor, aside from 

 the loss of life, was the expenditure of 

 sweeping gear. Thousands upon thou- 

 sands of fathoms of serrated sweep-wire, 

 together with more than fifty plunger 

 kites, had been blown away by the ex- 

 ploding mines. Our original estimates 

 had not anticipated so large a loss for the 



entire barrage as had been expended by 

 this single operation. Moreover, both of 

 these articles were exceedingly difficult to 

 obtain. 



Our present rate of work was far too 

 slow to complete the barrage within the 

 year, and even the thought of the idle 

 winter days in that miserable climate, 

 while we waited again for spring weather 

 to resume operations, was most disheart- 

 ening. 



WORKING EIGHTEEN HOURS A DAY 



Every minute on the mine fields was 

 being utilized. In that high latitude, 

 where the summer days are so unusually 



