Evening star. [volume] (Washington, D.C.) 1854-1972, 1923-05-20
RADIO GOSSIP AND NEWS

Why Washington is deaf to the
radio salutationS OF Baltimore, and
why many other cities of the, country
similarly arc mot on speaking
terms" etherally. with their close
neighbors, presents a problem which
radio experts have been unable to
explain.
Washington is also called dead
spot which turns deaf ear to its
nearest neighbor. Baltimore Opera
tors and experts agree that it is al
most impo ibIe to conduct satisfac-
tory radio communication between
the two cities, messages broadcast
from the Monumental city passing
"over the head" of this city and vice
versa Many theories have been ad
vanced in explanation of this sci
Sntific mystery, but-experimenters ad-
nit that most of them have failed
TO clear up the situation.
About 1880 miles from New York
, on the way of Rio de Janciro. signals
from Washfrg%ou-reHST 70 be heard
for forty eight hours. after which
they como again strongly and then
arc work able to the limit of the sta
tons isignl range.
There ---SGNsIa+-rpittcrS. at sea
where intervening mountains prevent
IN tAs' other. side. The peak of
TenertRe. acts as an effective "blan-
ket'' hFtween- the. Teneriffe station
and vessels approaching from the
north. ! !, =
was moved to- overcome a similar
diriculty.i Vessels sailing from Cape
Town to Durham cross an ocean
stretch where the Cape Town. signals
are unheard.
One of the best known dead spots
to mariners is In tho; Red sea, about
one days steaming from Alden. Ships
passing through this region can read
no signals from the Alden, station. but
on leaving II messages are suddenly
picked up again at full strength.
rFrom a certain position in the
Mediterranean vessels cannot get
their signals to. Port Said. whereas
messages from vessels and stations
farther away but at different angles
are read perfectly.
The perfect reception of wireless
signals, rand especially of telephon-
ing, depends mainly on the power of
the transmitter and the sensitiveness
and active tuning Of the receiver.
Tesose are known factors, but there
DIRE others which are largely mysteri-
ols even to experts.
Some localities are known as dead
spots though for this there Is no
explanation. while others are said to
be "screened" by iron or other ore in
the neighboring hills. On the other
hand, there are certain extraordinarily
sensitive areas-in which signals can
be read either with unusual clearness
or at exceptional DISTANCES.
The most pronounced of the dead
spots,,t however, appear to be be-
tween Washiagton and Baltimore. To
get message between these points.
less than forty miles distant, Wash
ington operators are using Chicago
and other remote cities as relay
points. 7e.-- -.
Some Washington radio opera tors
believe that thes~electric railway
lines between here and Baltimore alb
serb the ether waves. while others at
tribute the. condition. to the great
number, Of high tension cables and
conduits binding the two cities -
An explanation which appeals to
baltimore scientists as among the
nQbrc plausible is- the Spresence Of
geological formations which may af-
feet the air; above them. DR.. William
Kouwenhoven. who has charge of
radio instruction and experimentation
at Johns Hopkins University, says