192 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1919. 
ments. The present state of the art indicates the certainty that this 
can be done. 
In the field of military aviation wireless telephony finds its great- 
est present opportunity for immediate service. The requirements 
of interairplane communication are such that the telephone is 
peculiarly adapted. The use of wireless telephony within an air- 
plane squadron at once makes possible the development of the squad- 
ron into a military unit wherein the various members are subject 
to the command of the leader in exactly the same way as military 
units on land and water. The development of airplane squadron 
tactics is therefore made entirely possible, whereas without the tele- 
phone it is considered that the difficulties of communication between 
various airplanes would have made such a development impossible. 
Communication between airplanes and ground stations comprises an 
equally important phase of the operation of military aircraft. 
Hitherto these communications have been chiefly those for directing 
artillery fire and the wireless telegraph has served this purpose 
reasonably well. The availability of the wireless telephone, however, 
will open up new possibilities in the use of airplane to ground com- 
munication, an example of which is furnished by the present opera- 
tions on the Mexican border. Scouting parties, accompanied by air- 
planes, traverse the extremely mountainous country, with airplanes 
preceding ‘the land forces and at intervals reporting their observa- 
tions. If we imagine each of the scouting parties to be equipped with 
receiving apparatus sufficiently portable so that it does not in any 
way interfere with the movements of the party, it is at once evident 
that they could, without delay, be kept informed of the observations 
of the aviator, by direct telephone communication. This extension 
of range of vision would be of immeasurable value. 
Developments which have occurred during the war period, while 
essentially of a military character, are immediately applicable to both 
military and commercial needs. ‘These developments point the way 
to further progress in the art which it is believed will, within a short 
time, establish wireless telephony as an important element in many 
phases of our military and commercial activities. 
