Improvements in devices for determining the position of moving aircraft at night
GB380326A
Improvements in navigational calculating apparatus
US1829614A
Vertical and horizontal angle measurer
US1762102A
Sound-direction-determining apparatus
GB289872A
Improvements in the method of and apparatus for determining the instantaneous position and the speed and direction of movement of invisible air craft by exclusively acoustic means
GB281960A
Improvements in or relating to range finders
GB258593A
Improved method of and apparatus for imparting lateral direction in indirect firing with ordnance and machine guns
GB254705A
Improvements in apparatus for laying guns
GB252159A
Improvements in range finders
GB244495A
Improvements in or relating to breech sights for ordnance and machine guns
US1684681A
Breech sight for ordnance and machine guns
GB242631A
Improvements in or relating to range finders
GB245034A
Improvements in or relating to range-finders
US1649538A
Means for receiving and sending directional sound rays
GB259320A
Improvements in or relating to means for receiving and sending sound rays directionally
GB234058A
Improvements in or relating to telemeters
GB224917A
Improvements in or relating to means for locating air craft in space
DE442973C
Arrangement for determining the location of covered sound sources
