The Anaconda standard. [volume] (Anaconda, Mont.) 1889-1970, 1899-02-09
FINDS MAGNETISM IN BRICKS.
Experiments Made by Professor Law
renee at Rochester University.

experiments Made by Professor Law
renee at Rochester University.
Probably the idea that humble red
brick would ever play any part in cleo
trical experiments has occurred to few.
However, this is just what a certain
lot of bricks composing pier at Rey-
nolds' laboratory did and will continue
to do SO long as they are within reason
able distance of the delicate electrical
Instruments used in the laboratory.
A suspicion that the above contingency
might exist has been in the mind of
Professor Henry e. Lawrence of the
University of Rochester for some time
past. That it is a reality he now feels
sure, and the methods he used to come
to that conclusion are most Interesting.
The professor, in collaboration with
Otis A. Gage, special student in cleo
tricity, began a series of experiments
covering some months. The perform
ance of the magnetometer which wars
used in measuring the magnetic power
of steel bar was the first cause for
suspecting that the bricks were other
than what their appearance would lead
one to think. The magnetometer had
rested on brick pier for the purpose
of making it plumb. Not long after
Professor Lawrence, While in Ann Ar
Dor, heard Of similar experience oc-
curing there. On his return the expert
never. Bricks of all varities were put
through any number of tests and the
great majority We're found to be mag
netic. Those manufactured by water
power. known as "hydraulic'' bricks,
proved to be exceedingly strong, one
equaling the power of a steel needle %
centimeters in length. This same block
of clay would make noticeable defec-
tions in comparatively crude instru-
"a oil 70
perceptibly.
One of the bricks. plain white one,
automatically pressed. possessed no
magnetism. A certain amount of lime
enters into the composition of white
brick, such as was used. and its pres
ence undoubtedly had much to do with
the absence Of magnetic power. 1t was
discovered that the bricks gained mag
netism in the presence of dynamo,
though the surrounding of the bricks
by wire coils made no perceptible differ
ence Heating the bricks served in a
measure to decrease the magne tism,-
though in each case a minute amount
was retained. T 81 ;,=-
To just what cause this is due neither
gentleman is ready to state. 1t is the
present opinion, however, that there is.
more or less magnetic in the clay of
which the bricks are made. The mode
of manufacturing is also thought to
have something to do with the phenom-
ena. AS stated above. the presence of
lime served to decrease the magnetism,
while the absence allowed of greater
power. The professor thinks the i'm
portance of his discovery obvious. The
slightest trace of unsupported magnetic
power in the structural part of the la
boratory is necessarily, fatal to nicely
of electrical measurements.
That clay, when worked ever so little
by human agency, gathers magnetic
properties has been thought for some
time. Eminent italian scientists have
made innumerable experiments in that
line during the past half dozen years.
Their greatest proof was found by ex-
perimenting with several examples of
ancient pottery which had been buried
for centuries. Crude as they were, mag
netism was found to exist in no UNI
certain uantities.-Rochester Demo-
crat and Chronicle. ~