1868.] DE SOLA — THE PRESIDENT'S ADDRESS. 451 



in his eye than that they are intended to mend roads ; and 

 the quarryman cuts out his slabs, the highest utility of which he 

 deems their appropriation to building or ornamental purposes. 

 Both crush or cut to pieces, in all the blindness of ignorance, the 

 fossil forms of unknown organisms contained in them, but from 

 which the geologist learns the botany and zoology of former ages 

 of the world, and which enable him to predict the great changes 

 to take place in the future. The achievements of geology are, 

 however, too numerous and important even to be glanced at within 

 my limits, but I would venture to say something respecting one 

 of its sub-divisions — Ichnology, or the study of fossil footsteps — 

 revealing to us wonders of the past such as the imagination of 

 even a Milton or a Dante could never conceive. 



Possibly Robinson Crusoe himself was not so much aston- 

 ished at the footprints on the sands of his desolate island, 

 as the naturalist who first saw the footmarks of birds on a slab of 

 sandstone which was turned up by the plough of an American 

 boy in 1802, at South Hadley, in the valley of the Con- 

 necticut River. From this valley, the tide of conjecture 

 flowed over other continents, until it seemed finally to settle down 

 into the theory that the Noachic flood had rolled over those sand- 

 stone slopes, the surface of which, when the waters subsided, was 

 so soft as to readily receive the imprints of a bird's foot. The 

 traces, then, were those by which the raven of Noah had written 

 the historical fact of his standing on the earth itself; and so the 

 foot-prints were finally set down as those of Noah's raven. For 

 another quarter of a century or more, this dictum of popular 

 ignorance remained uncontroverted, men of science paying but 

 little attention to it, until a Scotch clergyman, Dr. Henry Duncan 

 of Ruth well, in 1828, called attention to fossil tracks in connection 

 with the sandstones of Corncocklemuir. Dean Buckland, by means 

 of his Bridgewater Treatise, gave wide circulation to Duncan's 

 discoveries, showing that these impressions were found through a 

 depth of forty-five feet of rock, not on a single stratum only, but 

 on many successive strata, thus demonstrating that they had been 

 made at successive intervals. The sandstones of Dumfrieshire 

 are supposed to have been wide-spread expanses of sand of a 

 littoral character, visited and covered by the ancient tides, some 

 of their surfaces, recording atmospheric conditions, being 

 sometimes pitted with hollows, the results of a pelting shower, 

 and these pittings have occasionally such a well-defined and dis- 



