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. 
