signal mirror:
Heliograph 3-inch Mark I - Front
signal mirror:
Heliograph 3-inch Mark I - rear
signal mirror:
Heliograph 3-inch Mark I from Top
signal mirror:
Heliograph 3-inch Mark I - left side
signal mirror:
Heliograph 3-inch Mark I - Right Side
signal mirror:
Heliograph 3-inch Mark I - arm underside
signal mirror:
Heliograph 3-inch Mark I - hinge partly open
signal mirror:
Heliograph 3-inch Mark I - latch detail
signal mirror:
Heliograph 3-inch Mark I in case
signal mirror:
Heliograph 3-inch Mark I Case - empty