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POPULAR SCIENCE REVIEW. 
Websterite at Brighton. — Mr. S. G. Perceval, F.G.S., states that in last 
July he observed that a deposit of Websterite, subsulphate of alumina, had 
been cut into, in excavating for the new system of drainage in the Mont- 
pelier Road, opposite the south end of Vernon Terrace. It occurs at a 
depth of 16 feet from the surface of the road, beneath a ferruginous deposit 
of varying depth, which overlies the chalk on the summit of the hill, consist- 
ing of ochreous clay with occasional flint-breccia and masses of haematite iron 
ore in some instances mammillated and associated with crystals of selenite. 
The iron ore is occasionally friable and of a cindery appearance, containing 
in its cavities angular pieces of chalk and occasional groups of crystals of 
selenite. The deposit of Websterite is about three feet wide at its junc- 
tion with the overlying ferruginous mass, narrowing as it descends, ap- 
parently occupying a fissure in the chalk, which has at some time been 
filled with clay, or has been formed by some decomposing action on the 
chalk, the chalk intruding occasionally into the vein of Websterite. 
Dr. Carpenter's Views Opposed. — Mr. A. H. Green contributes a very able 
paper to the “ Geological Magazine” (January 1870), in which he analyses 
Dr. Carpenter’s argument. Can, he asks, then, the fauna of the sea on 
whose bed the chalk of to-day is forming be said, on a broad view , to be the 
same as the fauna whose remains are preserved in the chalk of Dover ? He 
is not surprised that certain low forms should be common to the two, because 
the conditions under which such creatures live do not in all likelihood in- 
volve that struggle for existence to which specific change is probably due ; 
they have ample space and ample sustenance for animals of their simple 
requirements. Some few forms, too, somewhat higher in the scale, seem 
to have lived on in u the dark unfathomed caves of ocean ” but little 
affected by the round of changes that have so largely altered the dwellers 
on the upper world, though here it seems that the modern representatives 
are only generically allied, and not specifically identical, with the older 
forms, a point of the highest importance. But, leaving these cases out of 
the question, are the two faunas, as a whole , a bit alike P Take one simple 
instance. The older chalk swarms with ammonites, scaphites, baculites, 
and belemnites, all well-marked and typical forms, not one of which will 
be embedded in the chalk of to-day ; and the old chalk has not yet fur- 
nished a single fragment of a marine mammal, many species of which will 
be preserved in the modem chalk. A palaeontologist would readily point 
out any number of similar contrasts between the two faunas; but what 
he has said will, he thinks, make it clear why it is that he cannot under- 
stand how anyone can say we are living in the cretaceous epoch, unless 
he at the same time asserts that the age of a geological formation is to 
be determined from those beds only which are formed out of Foraminifera, 
and by the Foraminifera alone of the fossils contained in such beds. 
MECHANICAL SCIENCE. 
The Tower Subway. — This tunnel under the Thames, which as an en- 
gineering work was carried out with so much skill and success, rather 
threatens to prove commercially a less satisfactory undertaking. At all 
