TO 
POPULAR SCIENCE REVIEW. 
Consequently, when a deep well is sunk in London into the 
chalk, the water rises to near the surface from the pressure of 
the water pent up in the basin. Wells of this kind having 
originally been dug in the province of Artois (Artesium) in 
France, have been termed artesian wells. 
In giving this brief sketch of the geological history of the 
area upon which London now stands, we have pointed out but 
a few of the great changes in its physical geography which 
have taken place. We have treated of the chalk and over- 
lying strata, but we have not referred to the older rocks, and 
when we state that these, so far as they have been proved 
in Britain, constitute a series no less than twenty times as 
thick as the beds we have noticed, we are as much lost in 
awe in picturing each successive change during their deposi- 
tion, as we are at the immensity of time that must have 
elapsed since the earliest stratum was laid down. Comparing 
this period to a year, the age of man has been but a second ! 
We have said enough to indicate the many interesting sub- 
jects which a study of the geology of London embraces.* One 
subject, however, and one, perhaps, more important to the 
people generally than any other, we have neglected ; this is the 
probability of coal under London, or beneath the cretaceous 
rocks of the south-eastern and eastern counties. This question 
was discussed by Mr. Prestwich not long ago in the Popular 
Science Eeview. It is now being put to the test by the Sub- 
Weald en Exploration. A boring is being carried on to prove 
the palaeozoic rocks in Sussex, and has penetrated to the depth 
of 300 feet, where the Kimeridge clay has been just reached. 
It seems probable that at least 1,000 feet of rock must be 
bored before the older rocks can be expected, and then the re- 
sults will no doubt throw considerable light on the vexed ques- 
tion of the probability of coal in this neighbourhood. It is 
needless to enlarge upon the benefits that such a discovery 
would confer, for although according to the Eoyal Coal Com- 
mission we have a supply calculated to last three centuries, yet 
the high price of the fuel is a great source of disquietude to 
the nation. It would seem strange indeed to witness mining 
activity near to London, and probably the finding of coal would 
re-open the neglected iron-mines of the Weald. 
* Those who wish to pursue the subject in detail should consult Mr. 
Whitaker’s “ Geology of the London Basin,” 11 Memoirs of the Geological 
Survey of England and Wales,” vol. iv. It contains an exhaustive list of 
other works on the geology of the district, and records of over 500 well- 
sections and borings. 
Mr. Whitaker has also lately constructed a large model of London and 
its neighbourhood, embracing an area of about 165 square miles, on the 
scale of six inches to one mile. This is exhibited at the Museum in Jermyn 
Street, s.w. 
