428 Proceedings of the Royal Physical Society. 



appealed to the marine shells contained in the so-called raised 

 sea-beach bed, to prove that a rise in the bed of the Forth has 

 taken place within a comparatively recent geological period. 

 In " The Lithology of Edinburgh," the instances adduced are 

 proved to be unsatisfactory, and neither in accordance with 

 the habits of the animals nor with the mode of distribution 

 of the materials of a sea beach. 



An attempt has lately been made to prove a rise of the 

 coast of the Firth of Forth within the historical period, by 

 an appeal to the so-called raised sea-beach bed deposits. It 

 is contained in a communication by Mr Archibald Geikie, of 

 the Geological Survey, and published in the " New Philoso- 

 phical Journal" for July 1861. Mr Geikie states that he 

 found " fragments of Roman pottery in a stratified deposit of 

 marine silt, the deposition of which was going on during the 

 Roman occupation of Britain." He says that " the strata 

 with which this bed of silt is connected lie 25 feet above 

 high-water mark, and are unequivocally those of the raised 

 beach ;" and therefore he infers that a rise in the land to this 

 extent has taken place here since the time of the Romans. 



In a communication to the Royal Society of Edinburgh by 

 Mr A. Bryson, " On Hasty Generalisation in Geology " it was 

 shown that this so-called marine silt-bed* (No. 5 of Mr 

 Geikie's diagram), supposed to be of the Roman age, contained 

 also abundance of broken pieces of recent pottery, fragments 

 of bone belonging to the sheep and ox, and bits of burnt coal 

 with vesicular cavities irregularly disseminated throughout 

 the mass. This sand-pit is situated on the south side of the 

 Junction Road at Leith, and at the foot of Bowling Green 

 House garden. The section in this sand-pit furnishes a re- 

 markable instance of old artificial deposits, bearing so close a 

 resemblance to natural beds, that experienced observers, not 

 geologically familiar with the locality, have entirely mistaken 

 their nature and character. I examined this sand-pit up- 

 wards of two years ago, with the view of tracing the lateral 

 extent inland of the marine deposits. The uppermost natural 



* This bed is not distinctly stratified. There is no trace of lamination, and 

 there are bits of burnt coal scattered throughout the mass. 



