unaided by panic, the escape of a single man, woman, or child in the
house. We should remember, that not merely on the first discovery of
fire, but when the building is actually in flames, the firemen are at
work within the walls; and that these men are protected by no immunity
but that arising from their own courage and self-possession.

THINGS TALKED OF IN LONDON.

_February 1852._

Professor Faraday's lecture, with which, according to use and custom,
the Friday evening course at the Royal Institution was opened, has
been the most noteworthy topic of scientific gossip since my last. The
subject, 'Lines of Magnetic Force,' is one not easily popularised,
otherwise, I should like to give you an abstract of it. One requires
to know so much beforehand, to comprehend the value and significance
of such a lecture. The learned professor's experiments, by which he
demonstrated his reasonings were, however, eminently interesting to
the crowded auditory who had the good-fortune to listen to him. He
promises to give us, before the close of the season, another, wherein
he will make use of that telescope of the mind--speculation, and tell
us much of what his ever-widening researches have led him to conclude
concerning magnetism; a science on which he believes we are shortly to
get large 'increments of knowledge.' Mr Wheatstone, too, having
produced a paper resuming his stereoscopic investigations, had the
honour of reading it before the Royal Society as their Bakerian
Lecture, as I prognosticated a month or two since. Of course in this
practical age the inquiry is put--Of what use is the stereoscope or
pseudoscope? With respect to the former, it is said that artists will
find it very serviceable in copying statuary groups; and a suggestion
has already been made, to adapt it to the purposes of microscopic
observation, as the objects examined will be seen much more accurately
under the extraordinary relief produced by the stereoscope, than by
the ordinary method. And it may interest astronomers to know, that Mr
Wheatstone believes it possible, by means of the same instrument, to
perfect our knowledge of the moon's surface and structure. For
instance: he proposes to take a photographic image of the moon, at one
of the periods of her libration, and a second one about fifteen months
afterwards, at the next libration, which, as you know, would be in the
opposite direction to the first. The two images being then viewed in a
ster