558 



THE WONDERS OF GEOLOGY. Lect. V. 



prey; and that their footsteps were covered with a thin 

 layer of silt at each reflux of the waves. 



The following remarks of Dr. Deane will convey an idea of 

 the colossal proportions of some of these imprints : — " I have 

 in my possession consecutive impressions of tridactyle feet, 

 which measure eighteen inches in length, by fourteen in 

 breadth, between the extremities of the lateral toes. Each 

 footstep will hold half a gallon of water, and the stride is 

 four feet. The original bird must have been four or five 

 times larger than the African Ostrich, and therefore could 

 not have weighed less than 600 pounds. Every step the 

 creature took sank deep, and the sub -strata bent beneath 

 the enormous load. If an ox walk over stiffened clay, he 

 would not sink so deeply as did this tremendous bird."* 



Mr. Lyell mentions having seen on the banks of the 

 Connecticut river, (at Smith's Ferry, near Northampton, 

 eleven miles from Springfield,) a space several yards square, 

 where the entire surface of the shale was irregular and 

 jagged, owing to the number of footsteps, not one of which 

 could be traced distinctly, as when a flock of sheep have 

 passed over a muddy marl ; but, on withdrawing from this 

 area, the confusion gradually ceased, and the tracks became 

 distinct.f 



Some fine slabs of the sandstone, covered with several 

 tracks of bipeds of various sizes, collected by Dr. Deane, 

 are deposited in the British Museum. A representation 

 of one of the small imprints of the natural size, with the 

 surface of the stone marked with hemispherical pits pro- 

 duced by a shower of rain, is given in Lign. 126.J 



The enormous magnitude of some of the foot-prints was 

 formerly deemed an insuperable objection to the interpre- 

 tation of these obscure vestiges adopted by the American 



* Boston Journal of Nat. Hist. vol. v. No. 2. 



f Travels in America, p. 254. 



t Consult "Medals," vol. ii. pp.810 -816, for particulars. 



