351 
THE GEOLOGIST. 
and a rapid rate of cooling produced a black glassy substance, quite opaque, 
unless it was cast very thin, and then it became semi-transparent. If it 
were desired to run the fused materials more quickly, a flux, such as soda, 
effected such a result. The practical utility of this invention became widely 
known, and an extensive application of it was made in ornaments of an 
architectural character, mantelpieces, window-sills, window-heads, string 
courses, capitals of columns, and monumental slabs, which were all cast 
from Kowley Eag ; and these, from the almost imperishable nature of the 
material, are likely to endure for ages. For reasons which it is not neces- 
sary to state, the works did not long continue, and have since been taken 
down. In 1852 Mr. W. G. Elliott, Ellsworth, took out a patent for the 
manufacture of pipes and other articles from mixed brick clay, limestone, 
ironstone, and oyster-shells. The product was a greenish-black vitreous 
material when run into press-moulds and afterwards annealed. There is 
very little difference between this application and that of Mr. Borgognon, 
and it added nothing which was not well known in the effects of heat upon 
minerals. In 1854 a patent was taken by Mr. J. T. Chance, of Birmingham, 
claiming improvements in the manufacture of articles from the mineral 
called E-owley Eag, in which the principal discovery, in addition to what 
Lad been known of its fusibility and of its adaptation for casting in moulds, 
was, that the fused mineral, unlike cast-iron, was capable of being rolled 
or pressed into the form of slabs, sheets, bars, and rods, all either with 
plain or rai^^ed ornamental surfaces. In fact, it could be treated in the 
same manner as plate-glass and some of the ductile metals ; but articles 
manufactured in this way required to be subjected to the process of 
annealing. Another discovery was made about this time, in which it was 
shown that it was possible to mix a quantity of coloured glass with the 
fused Eowley Eag, for the specific gravity of basalt and common glass, 
when in a state of fusion, are nearly alike, and advantage was taken of this 
to produce sheets of the material which, when polished, resemble the rich 
and beautifully-coloured serpentines of Cornwall. In fact, there was no 
limit to the variety which could have been obtained by the admixture of 
these two and other substances,— the only point of any scientific interest 
in the matter being that the two materials did rot chemicallj^ combine, even 
with the greatest amount of care and skill. They were only mechanically 
mixed together, and the result is well shown in the specimens upon the 
table. In 1855 Mr. Chance and Mr. Adcock took out a further patent for 
improvements in casting articles from the slags of iron furnaces, but this 
chiefly related to the machinery and method of casting in sand moulds in 
place of the iron moulds first used by Mr. Borgognon ; and since this 
date no further discoveries appear to have been made in the practical appli- 
cation of the basalts and traps for economic purposes, or in the aid of the 
decorative arts. 
The specimens exhibited by the author, in illustration of his paper, were 
obtained from Mr. Adcock, the inventor and proprietor of the Basaltic 
Stone "Works, at Oldbury, "Worcestershire, after the works were discon- 
tinued ; namely, Eowley Eag in its natural state; a shining opaque 
glass — artificial obsidian — the common result of the Eowley Eag when 
cooled ver}- quickly ; specimen showing the conchoidal fracture, which is 
common to the fused as well as to the natural state of the Eowley Eag ; 
specimens showing different amounts of recrystallization in accordance 
with the rates of cooling (in one the greatest degree of change ever ob- 
tained was shown, other than its entire conversion into basaltic stone) ; a 
specimen showing that in some instances the recrystallization takes place 
