Geological Survei/ of the State of New York. 95 



current, therefore, setting down from the ocean into the bay, 

 must prevail during the six hours of depression ; and an equally 

 strong current setting down from the bay into the ocean, must 

 prevail during the same period of elevation. Granting these con- 

 ditions, we should be authorized, on the principles of hydrody- 

 namics, to expect tides of extraordinary height at the eastern an- 

 gle of the bay, and that a reflex influence would be experienced 

 along the line of coast westward. Were the position of the Bay 

 of Fundy reversed, so that it should open easterly into the At- 

 lantic, all that is extraordinary in the phenomenon we have been 

 considering would probably disappear. 



The possible bearing of our argument on the subject of mag- 

 netic polarity, is sufficiently obvious. If the magnetic line at 

 any given place is the resultant of all the magnetic influences in 

 the body of the earth, then whatever cause aflects the figure of 

 the earth will affect the position of the magnetic line. Whatever 

 the causes of the subordinate oscillations of the needle may be, 

 it is not doubted that they are connected with the diurnal and 

 annual motions of the earth. Admitting then the existence of 

 internal tides, there is no absurdity in the supposition, that the 

 distribution of the magnetic influences may be so far aflected by 

 them as to impart to the needle a sensible irregularity, whose pe- 

 riod shall be a lunar day, and whose amount shall vary monthly 

 and annually, according to the different relative positions of the 

 moon, the sun, and the earth. It may not therefore be a matter 

 devoid of interest, to settle by accurate observation, whether the 

 minor oscillations of the magnetic line be or be not connected, 

 in any degree, with the lunar motions. 



Hamilton College, May 10, 1840. 



Art. XIII.^ — Notice of " Third Annual Reports on the Geological 

 Survey of the State of New York, to the Assembly, Document 

 275, Feb. 27, 1839 ;" by Oliver P. Hubbard, M. D., Professor 

 of Chemistry, Mineralogy and Geology in Dartmouth College, 

 New Hampshire. 



The Report of 1838 received an extended notice in this Jour- 

 nal, Vol. XXXVI, p. 1, in which the results of the labors of the geol- 

 ogists were fully exhibited. The Report of 1839 need not there- 



