TRANSACTIONS OF THE SECTIONS. 67 
to large fractures or faults. This priority appears to be most reconcileable with 
what is now to be seen. If the Pennine Fault had been first, it might naturally 
have been expected to have extended in a straight line northward towards Esk- 
dale; but it does not extend beyond the line of the Tynedale Fault; and, on the 
river Irthing, the beds are remarkably regular, in a dip 8.8,W., and without any 
trace of faults, running north and south. Again, the Tynedale Fault might perhaps 
have been expected to penetrate the Pennine chain at this point of supposed de- 
pression. On the other hand, the previous existence of the Tynedale Fault, as a 
vast cross fracture, might be expected not only to influence the subsequent eleva 
tion of the chain, but also to cause the divergence of the “edge beds” of the Pen- 
nine Fault towards the N.E., and, in part, to deprive that fault of its usual power. 
Both these effects appear to be still visible; yet, after all that has been said, there 
is abundant scope for further observation and reasoning. 
On the Physical Condition of the Earth in the Earlier Epochs of its History. 
By the Rey. Jamus Brovin, Mommail. 
The author maintained that the condition of the earth in the earlier epochs of its 
history may have been the effect, not of internal, but of external heat, in the fol- 
lowing propositions :—1. The greater heat of the temperate and polar regions, in 
the earlier eras, cannot be accounted for on the supposition that the distribution of 
land and water was different from that which now exists. 2. The change which 
seems to have been produced on the metamorphic rocks was not caused by heat from 
within acting upon them while they were covered with a mass of superincumbent 
strata. 3. We lave no conclusive evidence that the temperature of the central part 
of the globe is higher than that of the surface. 4. There is no evidence that the 
great mass of the earth has ever been in a fluid state. 5. All the phenomena 
hitherto observed may be satisfactorily accounted for on the supposition that the 
earth was at some former time exposed to great external heat. 
The general inference which he deduced from his observations was that, in all 
Spee avons in regard to the physical condition of the earth in former epochs, it 
should ever be kept in mind that an increase of temperature implies an increase of 
Sepeephenc pressure, with all the effects on chemical combinations and animal and 
vegetable development which such an increase would produce. 
On Artificially produced Quartzites. By AtmxanpER Brysoy. 
The author gave in detail the results of experiments he had lately made with 
certain siliceous minerals. A brown crystal of Cairngorm quartz, exposed to the 
heat of a brick-kiln for six days, lost its carbon and came out white, having, never- 
theless, increased in specific gravity from 26458 to 2.6571. An amethyst treated 
in a like manner became changed into opal; red granite of Peterhead so exposed 
tumed white, but black basalts came out red, and the colour of Arran pitchstones 
was found to be permanent. He also exhibited a slice of silicified monocotyle- 
donous wood with annular layers, in which the crystals of silica were observed 
to have broken up the tissues of the plant. Referrmg to the question of fluid in 
inet rocks, he believed that no cavity had been filled at a higher temperature 
than 94°, 
On the Causes of Earthquakes and Voleanic Eruptions. 
By J, ALEXANDER DAVIES. 
The theory of the author was that these phenomena, generally preceded by 
atmospheric alterations unusual in degree, were also connected with them, and, 
indeed, caused by them. 
On Two New Coal-plants from Nova Scora. By Dr. Dawson. 
One of the plants (Z. Acadianus) belonged to the genus Lepidophloios of Stern- 
berg; the other was an example of a type of Lepidodendron, very characteristic, in 
Nova Scotia, of the Lower Coal-measures associated with the Lower Carboniferous 
Limestone. The author concluded that the original species of er ne (t. Lari- 
