DRIFT-SANDS AND THEIR FORMATIONS. 535 



often resembling mountains, wliicli for the most part follow tlie 

 trend of the steppe, as well as tlie direction of tlie prevailing wind, 

 wliicli is here from southeast to northwest. The hills rise, count- 

 ing from the nearest valleys, to a height of fifty-five metres, in- 

 clining gently on the windward side, but presenting a steep slope 

 on the lee. This steppe has indeed always in historical times in- 

 cluded bare spaces, varying in number and extent according to 

 the existing state of cultivation. Till the beginning of the pres- 

 ent century the bare drift-sand had so gained the upper hand that 

 there was in the middle of the tract a continuous extent of one 

 hundred and fifty square kilometres in which grass and shrub- 

 land could be found only in small spots and streaks. Only the 

 northeastern and southeastern part of the steppe consisted of 

 grass-land, in which bare spaces were likewise not wanting. 

 Many other such sand-districts might be named. For example, 

 there were in the County Pesth, in 1809, nearly 1,600 square kilo- 

 metres of more or less bare, but not continuous sands. 



Let us inquire into the origin of these sand-masses. The open 

 sea is usually bordered by deposits of sand and gravel. Where 

 the shore rises in steep rocks, these deposits are concealed under 

 the water ; but where the coast is alluvial, as is generally the case 

 in the smaller seas, the whole shore consists of sand and shingle ; 

 and the sea-drift extends up upon the dry land. The waves are 

 constantly bringing up new material to the beach, chiefly consist- 

 ing of fine sand. A storm stirs the water to a considerable depth, 

 pushes the sand forward, and bears it with the waves high upon 

 the shore. On the retreat of the waves, a part of the sand remains, 

 because it is specifically lighter than water. When the storm has 

 subsided, and the sea has withdrawn to its proper limits^ the sand 

 becomes dried, and falls under the power of the strong, restless 

 wind, which takes up all the fine particles, and when it rises to be 

 a storm wind some of the coarser ones too, and carries them away 

 into the country. Here it meets impediments of various forms 

 and efficiency ; then it drops its load irregularly, and gradually 

 piles up along the shore those hills which are generally known as 

 sea-coast dunes. 



This edging of dunes which borders the flat sea-shore is of va- 

 rious breadths in different places. In some places it becomes so 

 piled up as to cause a retreat of the waves. New dunes are con- 

 stantly formed farther toward the sea, and the dune-zone is 

 widened. Sometimes the widening is effected by the emigration 

 of the bare dunes toward the interior. In other places the dunes 

 are broken into by the sea-water, and suffer loss of breadth. 



When there is no overflowing of the shore or breaking up of 

 the dunes, the system usually consists of three more or less con- 

 nected rows of hills. First, the fore-dunes, which first receive the 



