Following
on from my post on heliographs one of my regular readers observed:
“Aiming a signalling mirror with the
sun behind you could be tough but basically if you have the sun behind you and
a plane in front, the problem (conceptually) is put the mirror flat between the
two.”
He
is correct. During my research I came across this informative illustration:
Note
that the signaller is using his free hand to aim by directing the reflected
spot of light on to it.
The Books
