THE STORY THE SEA TOLD 157 



you had looked for your footprints and the 

 marks of the rain-drops you would have found 

 they had disappeared. Perhaps they were act- 

 ually destroyed by the action of the waves, if 

 the sea was rough or the wind strong, but more 

 likely they were merely filled up with fine 

 mud or sand and could not be seen, although 

 still remaining in the material beneath the new 

 covering. Again and again the tide will rise 

 and fall, each time depositing more and more 

 silt and sand over your footprints and the rain- 

 drops and the myriad other marks until, at 

 some distant time, many feet of hard, compact 

 sand and mud may cover the smooth surface 

 whereon your footsteps were deeply im- 

 printed. Each of these succeeding layers of 

 material bears other marks and each is a page 

 of the sea's story covering the one beneath. If, 

 in years to come, you could carefully turn back 

 each of these mud or sand pages until you ex- 

 posed the one upon which you walked, you 

 would doubtless see your footprints sur- 

 rounded by the impressions of the rain-drops 

 and, even if by that time the sea had receded 

 and the flats were high and dry, you would 



