The Prince George's enquirer and southern Maryland advertiser. (Upper Marlborough, Md.) 1882-1925, 1901-07-19
NO.. 29
NEW TIDE RECKONING
MACHINE.

A machine that will do the work of
thirty expert mathematicians is being
constructed by the Government in its
scientific instrument shop on Capitol
Hill in Washington. 1t is to be an
improvement on an instrument in the
bureau of the Coast Survey which
has charge of calculating the tides.
This machine will he in class all
by itself as mathematician. Eng
land has one which does similar class
of work, but does not carry it SO far.
The British instrument was invented
by Lord Kelvin. The American
instrument was contrived by E. Terrell
all employee of the United States
Coast Survey.
The American machine now in use
cost s. 500. 1t stands about two feet
high and is eighteen inches across.
Its halt foot Of depth is a maze of
wheels, pulleys and levers. 1t does
wonderful things. There is little
crank on the lower left-hand side, and
at a simple turn of that crank the ma
chine will give the answer to a pro-
blem involving nineteen separate cal
culations. The problems it works
out are the enormously complicated
calculations of tidal variations.
In the year 1908 some ship will be
in the harbor Of Karachi, India, at
the head of the Arabian Sea. Sup
posed the ship arrives at $50 in the
morning on the first day of October.
The captain will have printed table
in his pilot house and in that table he
will read that at that particular hour
of that particular year there is seven
feet of tide in the bay. By referring
to chart showing the depth of the
bay normally he will show just how
much water there is in his vessel.
The calculation by which it is pos.
sible to predict seven feet Of tide at
that place and time was made by the
United States Governments machine
on May II last in Washington. The
machine owned by the British Gov
ernment is the only other one by
which the calculating could have been
done but on account of the enormous
volume of such work to he done the
two Governments Try to divide the
territory.
Foreign Governments have fire.
quently applied to the United States
to do some tide forecasting for har-
bors important to their commerce with
the machine invented by Mr.. Terrell,
which the new one is expected to
supersede. They have been quite
willing to pay for such work, but as
rule the Coast Survey has been un-
able to comply with such requests
owing to the pressure of its own
work.
Or. r. A. Harris of the Coast Sur
vey devised the plans for the new ma
chine now being constructed. He has
taken suggestions from the two in
struments now in existence and hopes
to produce one which will combine the
good features of both.
The employment of mechanical ap-
paratus for doing work usually per-
formed by the human mind is more
extensively seen in the Government
scientific departments than any other
place in the country. The multiply.
ing and dividing machine, for exam
pie, is a great saver of time and men
tai labor-not to mention its absolute
accuracy. The machine declines to
make mistakes, and if the operator
tries to make seven 60 into six, will
ring a bell in protest.
Practically all the adding in the
Governments Coast Survey work is
done by machines. Where the col
umn contains three-quarters of a mil
lion figures, as frequently happens in
the tide computions, the saving in
mental effort is very considerable.