BRITISH ASSOCIATION MEETING AT NEWCASTLE. 
371 
bands of varying flexure, the result vras, of course, such as would be pro- 
duced by contortions of alternating strata. Another effect was gained by 
having one end of a model held tightly and leaving the other free, so that, 
according to the pressure used and the curvature produced, the loose ends 
overlapped each other. 
On a Deposit of Sulphur in Corfu. By Professor Ansted. — The 
island of Corfu and the other Ionian Islands, as well as the adjacent main- 
land of Greece, consist almost entirely of limestone. A chain of limestone 
mountains, ranging east and west, crosses the island of Corfu at its north- 
ern extremity, and as this is transverse to the general direction of the 
mountains on the mainland, and also to the geographical axis of the island, 
it may be regarded as a spur rather than a principal range. Crossing the 
pass of Pantaleone, a few miles beyond we come to the village of Spagus, 
the walls of which are built of gypsum. In the pieces of gypsum it is not 
rare to find yellow markings and patches of native sulphur. Leaving Spa- 
gus, a path leads by a deep ravine to a small quarry about a mile and a 
half to the north-west. Probably about a mile further beyond the ravine 
a small cutting presented a section about 8 or 10 feet high, and perhaps 
20 feet in length. Here simple quarrying operations had been carried on. 
From the surface to the bottom of the quarry there were bands of gypsum 
nearly horizontal, and between them, somewhat irregularly, bands of na- 
tive sulphur, varying in thickness from a quarter of an inch to an inch or 
more. There were also large masses of sulphur not continuous. All the 
gypsum gave forth a strong sulphurous odour \^ hen tappedwith the hammer. 
From this little opening he was told that five tons of sulphur had been re- 
moved and used in the neighbourhood for the vines. He was informed that 
below these seams there was another thicker, at somewhat greater depth, 
and that for a distance equivalent to five English miles towards the coast 
to the north and west, a similar deposit was known. 
PoRPHYRiTic EocK OF Charnwood Forest. By Professor Ansted. — 
Tiie part of England referred to is a small district in the county of 
Leicester, east of the various other developments of igneous rock in 
England. The object of this paper was to show that the rocks, consisting 
of syenites, granites, and others of the appearance and character ejenerally 
regarded as igneous, were really of the same date as the slates with which 
they seem to alternate. The area concerned is only eight miles in length 
and not more than five miles across ; but within that space it contains a 
singular variety of the rocks usually called igneous. For the sake of con- 
venience the author called them pori)hyries, including all under that 
general name. They all contain nearly the same mineral composition. 
The slates are found disturbed by an antichinal axis, and are turned round 
at the southern extremity ; but with that exception all dip in the same 
direction on both sides of the granites and syenites. There are also in 
many places very well marked alternations and passages by which the 
slates may be traced into granite. This perfect gradation is one of the 
geological characteristics of the district, and, combined with the extreme 
variety of rocks of the granitic kind, render the whole of Charnwood 
Forest typical in English geology. It is clear either that the slates were 
originally a continuous submarine deposit, of which certain parts have 
since become porphyries, or that the slates were formed from clay at suc- 
cessive intervals of time, — the time being long enough, and the change of 
level great enough, to admit of the conversion of clay into slate on each 
occasion, while each interval was also marked by the outpouring of igneous 
rock, — or else, that the slates were cracked in the plane of their bedding, 
and the granite thrust through without disturbing the dip. 
