U. S. B. F.— Doc. 890. 



Plate XVII. 



FIG. 1.— LOWERING THE DREDGE. 

 (Photofrom Prof.E. N. Cory, Maryland State University.) 



Fit... 2.— EMPTYING THE DREDGE. 



In this case the dredge has been lifted by a donkey engine, part of which may be seen at the right. 

 (Photofrom Prof. E. N. Cory, Maryland State University.) 



