, 1865-07-28

= OOSN A"~ W
two at Burlington House, which, though
not graced by the fair sex. were singular
ly attractive by reason of their illustra-
ton of the progress of art and science, as
will appear from a few particulars.
We lave on former occasions noticed
aluminum-bronze as a metal combining
in an extraordinary degee the qualities
Of strength and lightness. Hitherto, it
has been only used for cups, trays, Jew
eiiery, and various domestic articles
but at the meeting above referred to, ex-
cellent proof was shewn of the adaptation
of alumlnum-bronze for scientific purpos-
es, chiefly In parts of surveying-instru-
ments, and supports and axes for tele-
scopes. In apparatus of this kind, it is
hardly possible to overrate the advantage
gained to observers by the combinations
OF strength and lightnesS possessed by the
metal and although the bronze is an in
tractable metal for casting, the difficulties
have been so we'll overcome, that large
tripods nave been cast in one piece, the
metal being nowhere more than about
one-tenth of an inch in thickness, and yet
capable of bearing a heavy weight. From
this, a fair notion of its strength may be
inferred.
1t is worth notice, by the way, that
machinery is coming more and more into
use in the manufacture Of philosophical
instruments, which is important, mas
much as machine-made instruments must
be accurate and identical. Hence, OBJ
servers in places widely separated, using
similar instruments, will be able to com
,,,r, +hoir Observations with rrooton oon
tainty than before. Moreover, it is found
that women can be e employed to attend
the machines, which will be a subject Of
congratulation among those persons who
have been trying to solve the problem
as to how unmarried women shall earn
their own living.
There were examples, also, of the fur
ther application of platinum to scientific
uses, IN which q considerable advance
has been made since DeviIle's discovery
that platinum can be cast in large masses.
For manufacturing chemists, platinum in
invaluable, for in boilers and other YES
sells made of that metal, they can con-
c|entrate the most powerful acids. One
Of these boilers, looking something like
a large bright tin kettle, was shewn
standing on a table !; its price was two
THOUSAND pounds.
A few years ago, magnesium was worth
forty g%uineas an ounce now it can be
bought at ten shillings an ounce, so
greatly has the cost of it's manufacture
been cheapened and it is now produced
as valves and screw-tubes of considerable
size and thickness, as we'll as in the form
of wire. It is also highly useful for ilIu-
minating purposes, and experiments have
been made with a view to its adoption
for street-lighting instead of gas. Of it's
brllliance, there is no question it throws
gas and all ordinary lights into shadow.
A Company in Rio J%aneiro, where gas is
sold at seventeen shilIings the thousand
feet, wrote not long ago to the secretary
Of a scientific society in London, to ask
whether magnesium could not be afford
ed at less cost, The inventive faculty is
so lively at the present day, that it is not
impossible a satisfactory answer may be
given before the world is many years
older.
Electric and Geographic signals appear
to multiply every month some simple
and effective, others curious and compli-