POPULAR SCIENCE REVIEW. 
116 
built with regard to the present sea level, since, in the case of the 
Antonine Wall, there is now sufficient space between it and the sea, at the 
Falkirk end, for a body of men to have marched round unperceived, while, \ 
both there and at the Kilpatrick end, the sea would wash up near to it 
were it twenty-six feet lower. 
And finally, the old Roman harbour of Camelon, in the valley of the 
Carron, is now five miles from the sea. Hence it is thought that the 
upheaval certainly took place long after metal had come into use ; while, 
from the position and nature and the relics of the Roman occupation, 
there is no reason why the movement should not have been effected since 
the first century of our era. 
Mr. Smith, of Jordan Hill, however, feels certain there has been no move- 
ment of the land in historic times ; while Mr. Carruthers has proved that 
the pottery, supposed to have been Roman, occurring in the raised beach 
at Leith, is really mediaeval, and cannot have a higher antiquity than the 
year 700, while with it occur tobacco-pipes. He thinks the deposit con- 
taining these remains is of late and artificial formation. But Mr. Geikie, * 
having since re-examined the locality, adheres to the conviction that it is 
a regular stratified deposit of sand and silt. 
Many years since, some enormous trifid footprints found in the Wealden 
strata were referred to gigantic birds. But, it having been ascertained 
that some quadrupeds, such as the tapir, place their hind feet exactly on 
the spots occupied by the fore feet, so as to obliterate the mark and leave 
impressions as though the creature had but two legs, a suspicion arose that 
these large imprints would be more accurately regarded as belonging to one 
of the huge reptiles entombed in the same rocks. Mr. Alfred Tylor has i 
described one of these markings, from Hastings, which measures two feet 
from toe to heel, and gives a beautifully-distinct impression of the foot. 
And, on comparing the proportions of the toe imprints with those of the 
bones of an iguanodon’s foot found some years ago by Mr. Beckles, so 
perfect is the correspondence that it is impossible to resist the conviction 
that the marking on the old rippled shore and the foot bones may both j 
be referred to the same creature. Mr. Beckles, too, has since described 
natural casts of foot-marks from the Wealden of Swanage and the Isle of i 
Wight, nearly three feet and a half long, and so distinct as to show not | 
only the toes but the sloping metatarsal bones. He thinks that other 
Dinosaurians besides the iguanodon made these tracks. 
The iguanodon, as restored at the Crystal Palace, certainly has five 
toes, though comparative anatomists are now of opinion there are two too 
many. Several other monsters, quite large enough to have made the 
markings, coexisted with it, but of their feet nothing is yet known. 
It appears that these foot-marks do not all occur on the same level, but 
at probably as many as four distinct horizons. 
The exact age of the sandstone blocks known as Greywethers has long . 
been uncertain, though all observers felt sure that these masses, so inte- i 
resting from their resemblance to the material of the Druid circle at 
Stonehenge, belonged to some part of the Eocene strata. Now, Mr. 
Whitaker finds that the places where they occur are exactly those where, 
by the London clay thinning away, the Bagshot sands would rest on the 
