31 



out of the opening between Tangier and Smith's Islands. The maximum velocity of the flood was 

 0.7 and the mean velocity 0.6 of a mile per hour. The velocity of the ebb was, maximum 0.8 and 

 mean 0.4 of a mile per hour. These curreuts were also measured during spring tides. Along the 

 eastern side of the Sound, below Jane's Island Light and over the several beds located on the 

 eastern edge of the channel, the general set of the current is to the northward on the flood and to 

 the southward on the ebb. The flood sets a little to the eastward or westward of north as the 

 channel changes in direction, and about the northern part of the Great Bock sets strongly to the 

 northward and eastward into the Little Annemessex. The ebb current out of that river forms a 

 strong tide rip where it joins the main current due east of Jane's Island Light and on the northern 

 part of the bed off that light. The general set of the ebb is the reverse of that of the flood, and 

 both currents follow the trend of the channel. 



Through the Thoroughfare, opposite the California Bock, the flood sets east into Pocomoke on 

 the first three quarters, and west on the last quarter. On the ebb the set is westward on the first 

 three and eastward on the last quarter, and this irregularity is communicated to some extent to 

 the waters over the California Bock. 



The maximum velocity of the flood current on the eastern side of the Sound, below the Little 

 Annemessex, was 0.3 and the mean velocity was 0.2 of a mile per hour. The maximum of the ebb 

 was 0.8 and the mean 0.7 of a mile per hour. Most of these currents were measured during 

 northerly winds, which would increase the ebb and diminish the flood currents, and probably they 

 are more equal than the observations show them to be. 



Over the Oak Hammock Bocks the flood sets to the northward and westward, and the ebb to 

 the southward and eastward, with a velocity of from 0.1 to 0.2 of a mile per hour. 



Beviewing the currents, it will be seen that the strongest on both tides were those over Terra- 

 pin Sands during the spring tides, their velocity being about one mile per hour. As the observa- 

 tions over the Sound were made during various states of the weather and of tide, the highest velocity 

 obtained is probably as great as ever sets over any of the beds. 



The velocity, except within wide limits, however, is not so important to the oysters as the 

 direction of the current, and that has been ascertained with, I hope, sufficient exactness to assist, 

 so far as it can. in the study of the beds. 



DEPOSIT. 



It would reqirire a much longer period of observation than was at our disposal, and a much 

 more extensive and careful investigation of the character of the water and bottom of the Sound 

 than I was enabled to make, to allow me to speak with authority or exactness upon this subject; 

 but from the information collected from the most intelligent of the oystermeu whose experience 

 on the beds was considerable, I am of the opinion that there is little or no systematic deposit going 

 on upon any of the beds of the main Sound. There must be some sediment contained in the 

 waters of the rivers and creeks, but it appears to be deposited on those beds near their mouths. 

 In the upper part of Fishing Bay, on the Clump Point Bocks, Middle Ground of the Nanticoke, 

 in the Manokiu and Big Annemessex Rivers, there is a larger amount of mud in the surface and 

 underneath than elsewhere in the Sound. Those beds lying in deep water are particularly free 

 from an undue proportion of mud on the bottom, the shoalest beds having the thickest mud 

 covering. 



If there was a constaut and increasing deposit upon the beds they would long ago have dis- 

 appeared, or at least have become of much smaller area, but the reverse is the case, the beds in- 

 creasing in area constantly. 



They are, however, exposed to one species of deposit which is very injurious. Heavy gales 

 occurring in winter and summer frequently tear up the large quantities of grass, sea-weed, and 

 sponge on the sand shoals about the Sound and deposit it upou the beds. If this occurs in sum- 

 mer, when there are a smaller number of dredgers at work, the effect is very injurious, the "cultch' ' 

 being covered, and the young, if spawned, smothered by the grass, weeds, sand, and mud which 

 it collects. The California Bock, Piney Island bar, and Mauokin beds are those most subject to 

 this evil. 



The gales also have the effect of covering the scattered oysters on the leeward sands, which 



