858 REPORT OF NATIONAL MUSEUM, 1904. 



account for all the geological phenomena hitherto attributed to the 

 mechanical action of water." The formation of such terraces as Hitch- 

 cock had described in the valley of the Connecticut he thought might 

 be % due to the action of waves and tides. He regarded it as idle to 

 suppose that existing streams have carved out their own channels, and 

 ridiculed the idea that the falls of Niagara were once at Lewiston, 

 seven miles below their present position, as had been contended by 

 the English geologist, Bakewell. 



He also decried all attempts at estimating the age of the falls or the 

 time before they would so far cut back as to drain Lake Erie. It w r as 

 his idea that the channel below the falls was cut while the rocks were 

 being slowly raised above the level of the great inland sea and forming 

 a limestone ridge or reef across which, at its lowest points, strong- 

 currents would alternately sweep during the ebb and flow of the tides. 

 As the elevation progressed the currents would become more and 

 more confined to the weakest and lowest points in the barrier, until 

 in course of time the whole force of the conflicting currents would be 

 concentrated at one, point. "The power of the waves and the influx 

 of the tide operating from below would be applied to the best possible 

 advantage in tearing up the strata which most impeded their course, 

 while the current, combined with the receding tide, would carry off 

 the fragments. In this manner the valley of the Niagara was doubt- 

 less formed." (See Hall's views, p. 384.) 



The lake beds of the region he imagined to have been formed by the 

 unequal erosion along the edges of uplifted strata, Lake Erie lying at 

 the junction of shale and limestone. Before this limestone had become 

 sufficiently elevated to shut out the sea from the basin now occupied 

 by the lakes he conceived a strong current to have set in through the 

 Gulf of St. Lawrence, finding its way through the valleys of the 

 Mohawk and Hudson, and dropping on its course the large quantity 

 of bowlders foreign to the localities now so plentifully distributed 

 over the surface. 



As earl} T as 1823 Governor Woodbury, in his message to the State 

 legislature of New Hampshire, had recommended an agricultural sur- 

 vey, having particularly in mind chemical investigations of the various 

 kinds of soils. It was not, however, until 1839 that, 



Jackson's Survey of . „ „. __ 



New Hampshire, under the earnest solicitation of Governor .rage, a 



1839-40. . ... . ° ' 



geological and mineralogical survey was organized, 

 and Dr. C. T. Jackson placed at its head. This survey continued for 

 three years, receiving annual appropriations of $3,000 to cover all 

 expenses. The final report appeared in the form of an octavo volume 

 of 375 pages, with two plates of colored sections and an uncolored 

 map of the State on which the various formations, or, rather, rock 

 types, were indicated by numbers. The localities of useful minerals, 

 peats, etc., were also indicated, as were the dip and strike of the more 



