330 -4. Theory of Fluxions. 



which here gives support to the trap rocks, and constitutes 

 the chief part of the precipice, being more than three hun- 

 dred feet high, and having the columnar trap resting upon 

 and scarcely attaining the elevation of a hundred feet above 

 it. The sandstone forms a projection beyond the trap which 

 is called by the inhabitants of the county " the offset." 

 This rock is stratified, and dipping at an angle of ten or 

 fifteen degrees, passes under the trap. It runs in the direc- 

 tion of the north mountains, which it probably supports 

 through their whole extent, as we discovered it in several 

 places along their declivity, as represented on the map. It 

 does not include any organic remains at this place, nor 

 veins of gypsum. At Finney's mills in the township of Wil- 

 mot it contains a bed of calcareous breccia, including no- 

 dules of hornstone, and small masses of radiated gray oxide 

 of manganese. The sandstone at this place is highly cal- 

 ciferous. This rock never distinctly appears on the coast of 

 the Bay of Fundy, although from the appearance of trap- 

 tuff containing fragments of it, we should be led to consider 

 it as not far beneath the accessible base of the precipice at 

 French Cross Cove. We have now finished our description 

 of the north mountains, which comprise the whole district 

 of the trap rocks in Nova Scotia, excepting the extremities 

 of the capes on the opposite side of the Basin of Mines 

 which remain to be noticed. 



(To be continued.) 



Art. XII. — A Theory of Fluxions* ; by Elizur Wright. 

 Sec. I. The nature of Fluxions. 

 The design of fluxions is to investigate the relations of 

 quantities that increase or decrease by degrees that are less 

 than any assignable one, that is, where the alteration of mag- 

 nitude is effected by one continued increment or decrement. 

 To illustrate the nature of fluxions by geometrical quanti- 

 ng- I- 

 ties, let us suppose that a a 5 .9 point, moving 



from A, generates the line AB=.r, this line is called a fluent. 

 Now if the point is conceived to move still onward, for a giv- 

 en time, with the same degree of velocity, which it had at B, 

 it generates the line BC=^*, called the fluxion. 



* Communicated by the author, to the Connecticut Academy of Arts and 

 Sciences, and published from their papers. 



