158 Fossil Footprints of the Connecticut Valley. 



of the pendulum, is not explained on precisely the same principle 

 which I had adopted. 



In another chapter in the same volume, the effect of the weight 

 when opposite the pendulum ball to lessen the arcs of vibration, 

 is attributed to mutual attraction, by some artists, and by others, 

 to the motion of the weight communicated by the pendulum, 

 and acting upon it reciprocally. 



So far as I have had opportunity to extend my inquiries among 

 practical horologists, I have found that the effect of confined air, 

 and especially the influence of the weight on the motion of the 

 pendulum when opposite the ball, and near to it, have been very 

 little known or regarded. 



On this account, perhaps the publication of these observations 

 may be of some importance, and may elicit a valuable communi- 

 cation on the subject. 



Providence, June, 1843. 



Art. XVI. — Description of Fossil Footprints in the New Red 

 Sandstone of the Connecticut Valley ; by James Deane, M. D. 

 (With a plate.) 



The impressions illustrated by Plate III, are footprints of ex- 

 tinct quadrupeds, from the new red sandstone of Connecticut 

 River; vestiges of unknown animals, of whose affinities we 

 have no other knowledge than what is derived from analogical 

 science. But the geological position of this rock assures us that 

 the epoch in which these inhabitants of an infant planet lived, 

 was immensely remote, and this antiquity alone invests them 

 with extraordinary interest. To see upon the smooth stratified 

 rock the successive steps of extinct animals, indisputable and 

 imperishable, sunk like a die, more perfect and inconceivably 

 more enduring than the proudest achievements of human skill, is 

 a sublime spectacle, because it creates the sentiments of sublim- 

 ity and awe. The history of fossil footprints, although of recent 

 date, is replete with amazing facts, yet we seem to have just 

 entered the vast regions of inquiry, for new developments are 

 constantly unfolding, some remarkable for grandeur of propor- 

 tion, and others for exquisite beauty and preservation. 



