Dialling friends, Like many of you, I have seen the signalling mirros with holes in the centre etc. I have never used one, but I have a mirror successfully to call in helicopters.
During field work in Antarctica, we didn't have radios, so we made up some signalling mirrors. Just a rectangular piece of mirror about 35 X 50 mm glued onto a lump of three-ply plywood. Sand off the sharp edges, and voila. The arangement was that were would be dropped off by helo, and the wander around doing our field work, and be picked up somewhere in the general vicinity. The pilot of the helo would approach our area of work with the sun more or less behind him, and we could flash him with the mirror really easily. Aiming was no great problem. Just hold the mirror in one hand, and hold up the other with fingertips just below the helo and in line with it. Gently twist the mirror so that the sun's reflection moves up off the fingertip and zap's the pilot's eyes. Dead easy when the helo is between you and the sun. One rather hazy day, I flashed a pilot just to see if it workd. The angle between the helo and the sun was about 120 degrees. One flash and he made an abrupt turn and landed beside a rather embarrassed John! No more randomly flashing pilots! Hope that throws some light on it all (groan, what a lousy pun!) John Dr John Pickard Senior Lecturer, Environmental Planning Graduate School of the Environment Macquarie University, NSW 2109 Australia Phone + 61 2 9850 7981 (work) + 61 2 9482 8647 (home) Fax + 61 2 9850 7972 (work)