BULLETIN OF THE UNITED STATES FISH COMMISSION. 44!> 



Vol. IIB, Jtfo. 29. Washington, II. C. Dec. 7, I 883. 



]OJ. SOTES ©IV THE MODEL OF THE GUEF OF MAIIVE CON- 

 STRUTTED FOR THE FNITEH STATES FISH C'OMiTIISSIOIV. 



By A. LIKDENKOHL. 



MODKL MADE FOR THE FlSH COMMISSION.— A Uiodel of the Glllf 



of Maine was constructed for the United States Fish Commission, in 

 order to exhibit clearly the geological construction of this part of the 

 Atlantic; this construction beiug of such an intricate nature that it 

 cannot be discerned with the distinctness and minuteness desirable 

 from hydrographic charts. 



Such charts, in general, are not the best medium to convey exact 

 conceptions of shapes of bottom for the reason that figures are employed 

 to denote depths instead of contour lines, and also for the more impor- 

 tant reason that there will always exist anomalies and deficiencies upon 

 such charts owing to imperfect methods of surveying. 



If soundings would furnish us a correct idea of the bottom, the pro- 

 duction of a faithful model would be a mere question of mechanical 

 skill ; but it is a matter of fact that whenever there is great irregularity 

 in the form of the bottom soundings only furnish indications of its shape, 

 and it requires considerable geological knowledge and familiarity with 

 the various molds employed by nature under given circumstances in 

 order to obtain an intelligible representation of the bottom. 



Holding these views, I think it incumbent upon me to submit a re- 

 sume of the results arrived at whilst engaged upon the model of the 

 Gulf of Maine, in order that those who are able to judge may determine 

 to what extent nature has been properly interpreted. 



Boundaries of the Gulf of Maine. — The term "Gulf of Maine" 

 was first employed by the United States Coast Survey to designate 

 that part of the Atlantic which lies between the eastern coast of the 

 New England States and Nova Scotia, to the northward of a line from 

 Nantucket to Cape Sable, and which connects with the Bay of Fundy 

 towards the northeast. 



Nantucket Shoals. — The Nantucket Shoals comprise a series of 

 narrow bands of shoal ground off the island of Nantucket, reaching 

 out in a southeast direction about forty miles. Besides ascertaining 

 their positions, the Coast Survey has developed the fact that the shape 

 of the shoals conforms in a remarkable degree to the directions of the 

 tidal currents. The flood current sets in from the southwest and the 

 ebb current from the northeast, both moving over the same ground in 

 reversed directions, which coincide with the major axes of the shoals. 



Tidal currents have not only given shape to the shoals but have also 

 abraded the island to a considerable extent. Nantucket Island con- 

 sists of sand and other drift material loosely piled uj>; consequently the 

 Bull. U. S. F. C, 83 29 



