'revenant' not forgetful of the great troubles of his own day, and
anxious to know how often London had been burned down since his time,
and how often the plague had carried off its thousands. He would have
to learn that, although London contains tenfold the inflammable matter
that it did in 1666; though, not content with filling our rooms with
woodwork and light draperies, we must needs lead inflammable and
explosive gases into every corner of our streets and houses, we never
allow even a street to burn down. And if he asked how this had come
about, we should have to explain that the improvement of natural
knowledge has furnished us with dozens of machines for throwing water
upon fires, any one of which would have furnished the ingenious Mr.
Hooke, the first "curator and experimenter" of the Royal Society, with
ample materials for discourse before half a dozen meetings of that
body; and that, to say truth, except for the progress of natural
knowledge, we should not have been able to make even the tools by which
these machines are constructed. And, further, it would be necessary to
add, that although severe fires sometimes occur and inflict great
damage, the loss is very generally compensated by societies, the
operations of which have been rendered possible only by the progress of
natural knowledge in the direction of mathematics, and the accumulation
of wealth in virtue of other natural knowledge.

But the plague? My Lord Brouncker's observation would not, I fear, lead
him to think that Englishmen of the nineteenth century are purer in
life, or more fervent in religious faith, than the generation which
could produce a Boyle, an Evelyn, and a Milton. He might find the mud
of society at the bottom, instead of at the top, but I fear that the sum
total would be a deserving of swift judgment as at the time of the
Restoration. And it would be our duty to explain once more, and this
time not without shame, that we have no reason to believe that it is