344 J. STANLEY GARDINER. 



at right angles to the slope. The appearance would hence be that of immense stone slabs, all 

 duly squared and laid on one another against a sloping bank. Sometimes there is as it were 

 a single slab, sometimes 9 or 10 apparently on top of one another. Often there are two or 

 more lines of such masses in a beach, each of one or more terraces, separated by hollowed 

 out sandy areas, and yet perhaps more often a single line at the base of the beach from 

 the half tide to the low water mark. Where the beach is steep or ends in a cliff, there 

 may perchance be as at Boni-Kodi, Minikoi (p. 32) an induration of the sand of that cliff, 

 but marked areas are only found on the shore, where the slope does not exceed 10°, and the 

 beach consequently is of considerable breadth. 



The varying conditions can of course best be seen by definite instances in different atolls, 

 which will be found in Apjjendix B. to this paper. The greater part of the evidence also 

 that any beach, where such formation is going on, is being washed away rather than growing 

 outwards on its reef must likewise be sought in the same place. It is, however, clear from 

 the consideration of the mode of formation of the sandstone that such must really be the case. 



The first appearance of the rock on different beaches varies considerably. It commonly 

 commences as a single broad line at the base of the beach, where it passes into the sand 

 or reef flat. Such a layer merges into the sand of the beach above and into that of the 

 flat below. Usually its rock is very soft, and can be easily dug out by a hammer or 

 crowbar. It does not, however, remain long in this condition. If the beach is growing 

 outwards on the reef, it becomes covered up with sand, and can only be traced as a slightly 

 more consolidated layer in the sand of the island. More often the waves overtop the layer, 

 and the sand above it is washed out, or the sand above may be removed by the wind. 

 The layer on the face of the beach has now become a definite terrace. 



When the sand above the layer has been removed to a dejith of about 5 or 6 inches 

 from the face of the beach, the first layer more or less protects the beach from further 

 encroachment, and a fresh layer commences to form. By this means 3 or 4 layers may be 

 found on a beach, the lowest merging gradually into the sand of the flat and the highest 

 almost reaching the high water mark. The water after every wave, that runs up the shore, 

 has somehow to reach the sea again. It naturally is hindered by each layer, along the top 

 of which it flows to make its escape at the lowest point. Its action here is twofold, firstly 

 in wearing away — partially by friction and partially by solution — the top of any layer, thus 

 reducing it greatly in breadth, and secondly in undermining the layer, forming natural crevices 

 by which the water joins the sea again. By this means more and more layers may be 

 formed, in one place on the beach at Duravandu, South Mahlos (Fig. 75), seven having been 

 thus fashioned. The water in its escape off the beach consolidates the sand under the top 

 layer of stone, and the second layer accordingly may be traced under the first. In a section 

 owing to this action all or most of the layers may be perceived, each layer being less 

 consolidated than the one above it, until about the third or fourth merges into the sand of 

 the island. 



The natives are thoroughly well aware of the second or undermining action of the sea, 

 and use it largely for obtaining their building material. A firmly consolidated layer is chosen, 

 and, where it immediately overlies the layer beneath, its top is hollowed out so that the 

 water may find a resting-place. When in a year or two the layer has become more or less 

 undermined, a series of cross-cuts is made with the result that in another year the whole 

 of the top layer can be wedged off in a series of slabs. In one of the beaches of the island 

 of Male this action even on coral rock was clearly seen in a square about 4i feet across, cut 



