154 Timehri. 



detritus from lands now submerged, and the alluvial plains of Guiana 

 were made by the ocean. 



The sea margins that one finds nearly parallel to the present shore, 

 as far as they consist of clay, were the action of the ground wave 

 rolling from the north-east on the shoaling mud bottom warping up 

 banks that at last reached the surface. 



The rivers only bring down sand and seem to deposit it chiefly 

 parallel to their fairway and at their sides. The Corentyne and the 

 Essequebo carry more sand than the Berbice and Demerara as evinced by 

 the conformation of the shallops at their mouths. 



Between these banks and the old shore lagoons would be formed, 

 which, receiving the drainage from higher grounds, and intersected by 

 rivers also adding their detritus and decayed leaves, would soon be 

 covered with vegetation. 



If the Atlantic waves at present were higher than they are, the same 

 thing would occur again, and a new reef would form outside. As it is, 

 the foreshore does not slope evenly, but undulates slightly, following the 

 shore line. The water rising with the tide, and receding with the ebb, 

 has a levelling tendenc}^ however, and where it has the greatest velocity 

 keeps the bottom deepest, in ratio of the quantity of water flowing over 

 it. It is therefore important that the greatest possible volume of water 

 should enter the estuary and flow out of it, and therefore the entrance 

 should not be narrowed, and it is to be regretted that the last extension 

 of the Best groyne should have been made to bear so much to the east. 

 The encroachment of the stellings on the river has also a pernicious 

 effect, as they act as so many silt catchers. They ought to be replaced 

 by a continuous quay. At all events, instead of extending them any 

 further, a limit line should be decided upon so as to form a straight line, 

 and a channel could then be dredged so as to allow large ships to lay 

 alongside these stellings. 



As groynes have but a very local effect, it can hardly be expected 

 that the east Best groyne would have deepened the bar. This bar is 

 not what is generally understood by that word, that is, a bank in a river 

 mouth formed by the river carrying down its own detritus and depositing 

 it where it comes in contact with the open sea. What is called the bar 

 here is really a deeper channel through the mud flats of the foreshore 

 caused by the sea flowing in and out of the estuary. 



In comparing the soundings of 1883, 1870 and 1879, on the bar, 

 this has diminished in depth during the first period from 11 feet to 9 feet, 

 and since 1870 to 8i feet, but has become wider. Whether the low 

 water-marks of the different years were the same is difficult now to 

 determine. 



The stronger blowing of the N.E. trades than for some time 

 previous, casting up more mud, are very likely the cause. 



