The sun., 1919-03-30

Of the allied forces relied upon wire
less telegraphy to signal back to the
batteries how to alter their elevations
and points OF attack. These signals
were comparatively few In number and
were made up Of a brief code which
tho pilot or the observer, as the case
might be, had learned in the calm OF
the training school. When lodging
anti-aircraft guns and defending air
planes 1t was difficult to keep the mind
on the 10y stick" Teuton machines.
and the telegraph key. Mistakes were
frequent, and at best the scope OF di-
regional communication was limited.
Not only that, but wireless Inter-
course from ground to flying machine
was but seldom satisfactory. because
the man up in the air was all too apt
to read the Morse code incorrectly.
The advent of the wireless telephone
transformed this situation, and our ex-
perts made it possible for flight
commander TO direct his squadron
vocally and to exchange speech with
his friends on the ground and miles
away.
There was no guesswork about what
was then expected of the fliers aloft
or OF the battery commanders be-
hind the lines. Communication was
positive, full and explicit. An air
plane transmitter OF the De Forest
type, the entire equipment Weighing
little over eighty pounds. was de-
veloped capable OF having a vocal
range OF twenty-five miles or Of being
used as a radio telegraph over a dis
lance OF 100 miles. The set possessed
a single oscillion tube.
The Western Electric Company did
wonders in the way OF making quantity
production possible and in evolving
special features that wore absolutely
necessary TO efficient working on the
part of the aircraft radio telephone.
To begin with the transmitting mouth
piece had to he designed in a way
that would facilitate the impressment
Of voice waves upon the transmitting
diaphragm and still he insensitive TO
,, the noises and wind currents peculiar
to the flying machine. Further. the
aviator had to be provided with a
| sound proof helmet in which could be
| placed the telephone receiver. and yet
It was essential that this hood should
in no wise interfere with his seeing
and breathing freely. Each one OF
| these problems was thoroughly mas
| tered.
The wireless telephone on fair sized
vessels is by no means a thing to
wonder at after airplane wireless
telephony came into Its own. for like
everything else far reaching in the
world OF electricity the factor Of ini-
tial energy determines the ultimate
range or reach. Space. weight and a
good many other helpful factors can
DO supplied well nigh without stint
aboard n big ship, and in principle
, the radio telephone set Is funda-
{ mentally not unlike that installed in
a submarine chaser. Such, broadly, is
the task of transmission; we have al
ready had the audion explained and
understand the part 1t takes In pick
ing up the wireless waves which may
be either the dots and dashes OF tho
Morse code or the eXQuisitely varied
impulses of speech waves.
DR.. de Forest has n six step ampH-
fer. having six little audions arranged
so that each one successfully intensi-
ties the vigor Of the electrical disturb
ances delivered to it from the audion
just ahead In line. In this way II Is
I possible to take extremely weak sig
mails and to strengthen them a million
times before they are made vocal at
the receiving ear piece.
The radio experts OF the navy and
their fellows of the army have all
! done their bit in promoting wireless
telephony during our participation In
the world war. 1t is hardly necessary
| here to name these men. But espe-
! cial credit should he given to Col.
c. c. Culver OF the Regular Army
This progressive cavalryman posse sses
| imagination and the gift to visualize
the value of technical advance, and