by puddlepirate » Sat Jun 21, 2008 10:44 am
Hi Ian
The other problem is that from the jetty the lighthouse doesn't throw out a beam of light as such, it just flashes...a tiny white light flashing in the distance. If you check a nautical chart or a nautical almanac such as Reed's, you will see the red light is much lower than the white and that it shows in sectors only visible along the coastline, not inland. The red light cannot be seen from the jetty and it certainly cannot be seen from anywhere either in the forest or along the edge of the farmer's field. Halt saw a red light and pursued it over the farmer's field. As can be seen in your photo, the field slopes down into what might best be described as a valley. As you stated in the text with your photo, there is only one place along the edge of the farmer's field from which the very top of the lighthouse can be seen; move from that spot and it is hidden. Halt's men were going down the slope so despite the fact they were chasing a red light not a white one, had they been chasing a white light even that would have disappeared from view as soon as they took a few steps into the field - yet they chased it down a slope and across the stream at the bottom of the field.
When standing at Chantry Point (see OS map Explorer 212) an observer will see the lighthouse from side on and get a clear view of the shield blocking the light from shining inland. Viewed from Chantry Point the shield looks like capital C and a line drawn from the lighthouse through Chantry Point, extends towards Crag Farm, about 1.5 miles south of the place on the edge of the field at Capel Green from where your photo was taken. Therefore, if an observer now moves up to the farmer's field from Chantry Point the shield becomes progressively more effective because the observer is now moving behind it. Therefore, because from inland the lamp is shielded from approx 000 deg right round to about 140 deg (from Halt's position the light bears 110 deg - which means he was on a reciprocal bearing of 290 deg from the lighthouse and well into the shielded sector) only a small fraction of the light could possibly be seen from the edge of the field. Irrespective of the fact that the light had a greater range (30 miles) in 1980 than now (20 miles), I find it hard to believe there would have been a beam sweeping through the forest every five seconds - plus of course, prior to the 1987 hurricane, the forest was, apparently, more dense than it is now.
In all honesty, to me it sounds like Halt and his men were chasing somebody mucking about with a powerful torch that had a red gel over the lens. The prankster gets to the road that runs through Capel Green then lets off a firework, at which time Halt and his men give up...
You can fool all of the people some of the time and some of the people all of the time but you cannot fool all of the people all of the time (Winston Churchill)...causa latet, vis est notissima
