920 



THE NATURE BOOK 



ONE OF NATURE'S TOWERS. 



of the cliff, and dislodging other rocks 

 that have been loosened bv the action of 



the rain and ice, sweep them downwards. 

 In this way immense blocks of stone are 

 split and wedged outwards down the cliff. 



Rain is one of the most useful tools that 

 Nature employs in her masonry, for in 

 falling it dissolves and absorbs the gases 

 of the air, and carrying these downwards 

 exerts a powerful chemical action on the 

 surface of the rocks. Those red-brown 

 stains, so familiar in sandstone districts 

 where the face of the cliff is exposed, tell 

 of chemical decay, caused by the oxygen 

 carried down by heavy rain making 

 hydrated iron oxides as it percolates 

 through the cracks and crannies. In the 

 same way rain, taking up carbon dioxide 

 from the atmosphere, attracts the lime- 

 stone and forms pits and grooves in the 

 surface of the cliffs. 



A very remarkable example of Nature's 

 masonry, chiefly formed by the action 

 of rain and frost, is the Agglestone, or 

 Haggerstone, which stands about i8 feet 

 high upon a sandhill near Studland. It 

 is an irregular weathered remnant of the 

 Bagshot Sands, that owes its preservation 

 to the induration of the sands, and forms 

 a most striking feature of the landscape. 

 It is only natural that this strangely 

 shaped mass, standing out weird and 

 isolated on the heather-clad plains, should 



THE AGGLESTONE IS A GIGANTIC WEATHERED REMNANT OF THE BAGSHOT SANDS. 



