THE WARFARE ON OUR EASTERN COAST 



209 



marks in places fully a mile inland. At 

 Absecon houses now stand at a point that 

 was low tide in 1850, while Sandy Hook 

 is now nearly 1% miles northwest of its 

 stated position in 1764, when the light- 

 house there was built. 



The shifting of the sands of the sea- 

 shore very often involves expensive liti- 

 gation. In 1885 the counties of Atlantic 

 and Burlington of New Jersey entered 

 into an expensive litigation concerning 

 the boundary between them. There was 

 a dispute as to one of the corners of this 

 boundary. It was stated to be, in the 

 original survey, "the next inlet in the 

 south side of Little Egg Harbor's most 

 southerly inlet, and thence along the sea- 

 coast to the line of partition between east 

 and west Jersey." But it could not be 

 found in its original home when they 

 went to look for it, thus bringing up to 

 date the ancient saying about a rope of 

 sand. 



THE TERRIFIC WAVE FORCE 



The unusual force with which the sea 

 attacks the shore is revealed by a series 

 of investigations made in Great Britain. 

 These show that winter breakers which 

 exert a pressure of three tons per square 

 foot are not unusual. Sometimes these 

 breakers have been so powerful that they 

 have moved blocks of rock exceeding 100 

 tons in weight. Ground-swells some- 

 times cover the cliffs of northern Scot- 

 land with sheets of water as high as 200 

 feet, while the Dunnet Head lighthouse, 

 whose windows are nearly 300 feet above 

 high-water mark, has occasionally had its 

 windows broken by stones swept up the 

 cliffs by sheets of sea-water. It is esti- 

 mated that the average force of the 

 waves on the Atlantic coast of England 

 is a ton per square foot throughout the 

 winter months, but much less in summer. 



The waves always find a most valuable 

 ally in the wind while their work of 

 coastline transformation goes on. The 

 possibilities of the wind as a worker in 

 conjunction with the waves are revealed 

 when we consider that during a violent 

 storm the air may hold in suspension as 

 much as 126,000 tons of sand to the cubic 

 mile. This sand, driven hither and 

 thither, finds a resting place somewhere, 



and that resting place is usually a dune 

 along the shore. 



THE CAVALRY OE THE AEEY 



A sand dune always has a humble be- 

 ginning. A piece of wreckage cast up 

 by the waves may start it, or any sort of 

 obstacle lying upon the shore may cause 

 it to come into being. Once started the 

 dune becomes a trap to catch sand in. It 

 takes its toll of every passing gust of 

 wind, and thus continues to grow and 

 grow. Often they keep advancing until 

 they bury orchards, forests, and even 

 buildings, like great drifts of snow (see 

 page 203). Along the coast of New Jer- 

 sey one may see orchards which have 

 been covered by wind-blown sand within 

 the memory of man so that only the tops 

 of the trees now protrude above the sur- 

 face. It is not exceptional to see a forest 

 invaded (see page 210) and sometimes 

 even completely buried. To watch the 

 struggles of the trees against their en- 

 croaching enemy is one of the most re- 

 markable sights of nature. As the sand 

 rises around their trunks new roots are 

 put out near the surface, and they con- 

 tinue to fight their battle month in and 

 month out, but generally they are finally 

 completely engulfed. 



Trees which are in process of being 

 buried under sand are equipped to make 

 a stubborn fight for their life ; on the 

 other hand one buried under water gives 

 up the ghost as soon as the water rises 

 above its roots. A water-submerged for- 

 est was never seen anywhere to better 

 advantage than at Panama when the 

 waters of the Chagres River were im- 

 pounded in Gatun Lake. 



The alternating burial and resurrection 

 of forests is due mainly to the tendency 

 of sand dunes to migrate. On Hatteras 

 Island, North Carolina, the migration of 

 a dune literally robbed a cemetery of its 

 dead, dashing down the gravestones and 

 exposing, the bones of the bodies buried 

 there, says Professor Cobb, an authority 

 on the subject of beach formations. 



On the northern end of Hatteras Island 

 a fishing village has been completely 

 buried, while the sand has entirely crossed 

 the island at several places north of Cape 

 Hatteras. This movement of sand was 



