NEW METHOD OF ENGRAVING MEDALS. 
497 
lar peculiarity of the dikiviura of Nor- 
folk. its containing large masses of 
chalk, and these have imbedded organic 
remains, differing in some respects from 
those of the chalk in situ. The town of 
Cromer seemed to be built on an im- 
mense block of chalk, contained in the 
diluvial formation.— Mr. Murchison dis- 
sented from Mr. Greenoiigh’s opinion. 
He conceived the formation of chalk was 
under the diluvium, and had been ele- 
vated and disrupted. He had seen at 
Hazeborough large platforms of chalklaid 
bare after a storm; near that place were 
needle-shaped rock’s of chalk, and at 
Cromer the foundation of the town must 
rest on part of the same mass. There 
were strong reasons for believing that 
the Norfolk diluvinm contained recent 
shells only. Mr. Lonsdale, on examina- 
tion, could discover no others. — Mr. 
Charlesworth mentioned that Dr. Beck 
considered the shells of the tertiary 
period to be extinct species, and that at 
the formation of the Norfolk Crag the 
climate must have been very cold, like 
the Arctic regions. He considers the 
diluvial formation to have been suffici- 
ently searched to warrant an opinion 
that it does not contain the remains of 
the mastodon. Many singular organic 
remains have been found there, which 
have been transported, as of saurians, 
which must have come from Yorkshire. 
In alluding to the fact of shells similar 
to those of the Crag being found at 
Bridlington, he was informed by Mr. 
Sedgwick that the formation at that 
place was probably part of the Crag. 
A paper, by Mr. J. G. Bowman, was 
now read, on the Bone Caves at Cefn, 
in Denbighshire. A description of these 
has been already published in the Phi- 
losophical Journal; and the proprietor of 
the place, Mr. Lloyd, was about refer- 
ing the investigation of its phenomena 
to Dr. Buckland. The cav’es are in car- 
boniferous limestone. The roof of the 
lower cave is covered with stalactites, 
which are often broken off or blunted. 
The diluvium on the floor contains 
fragments of slate, and the upper portion 
animal remains in great abundance 
Among these are some of a very minute 
size, and also elytra of beetles. A black 
matter is also found, with veins of red- 
dish clay. 'I'he bones are often in frag- 
ments, the teeth are something worn ; 
sometimes the teeth of young animals, 
but no indentations have been found 
upon them, No skulls have been dis- 
covered, nor any caprolites. The bones 
frequently contain gelatine, and have 
often manganese upon them ; hair was 
also discovered. The stalactites seem 
confined to the anterior part of the 
cave ; in the posterior j)art a fine sand 
is found. 
After this, a desultory conversation 
took place on the exhibition of two mo- 
dels by Mr. Ibbotson, one of the country 
round Neufchatel, in Switzerland, and 
the other of a part of the Under Cliff in 
the Isle of Wight, extending from 
Biackgang Chine to St. Laurence. 
Mr. Greenough mentioned a new 
mode of engraving medals lately adopted 
in France, and which he conceived 
could be advantageously employed in 
laying down the varieties of surface on 
maps.* — Mr. Griffiths spoke of th® 
great importance of models, like Mr, lb- 
botson’s, as being so well calculated to 
display the geological structure of a 
country. He suggested the importance 
of possessing maps, both of outline and of 
features, and he alluded to the magnifi- 
cent map of Ireland, under the Ord- 
nance Survey, the scale of which, being 
six inches to a mile,enabled the geolo- 
gical observer to trace the geological 
features with a facility before unknown. 
It was mentioned, that the new map of 
Austria was on a scale of twenty-two 
inches to the mile, but this Mr. Gree* 
nough considered inconveniently large. 
Mr. Ibbotson stated that models could 
be easily raultij)lied by employing a 
metal mould, and using papier mache, 
or some preparation of caoutchouc ; and 
that they might be dissected to exhibit 
the internal structure, and that mate- 
rials of the strata themselves could be 
used as colouring matter. — Lord Nor- 
thampton and M. de la Beebe gave 
their testimony of approval. — Several 
gentlemen then spoke of the application 
of combinations of letters to geological 
map.«, to express the more minute geo- 
logical ])henomena; but the general 
opinion was, that in geological maps 
simplicity should, as much as possible, 
be preserved, and that the best mode 
would be to have two maps of the same 
district, one without names, for the geo- 
logical map, and the other with the ne- 
• We shall take an early opportunity of 
giving some informatioa on this iuterestiug 
subject. 
