NavList:

Eamonn

'Could the members throw some light on the method referred to here and its history.'

..... If you were to come by an old time Navigation text such as the one written by Squire Lecky,

you would find very little mention of a method for Longitude, but many chapters describing techniques

for 'determining the local time', (and hence Longitude, or find the chronometer error if beside a local marker of pre-known longitude).

That was how it was done before folk had charts cheap enough to plot on, mariners just kept a log of Lat and Long.....

and

'The marker is also referred to as a "Harbor marker"

Do any of these markers still exist?'

.....The Harbour markers are like weeds along the coasts, only these days we call them lighthouses (and similar).

Their Lat and Long are published in almost every historic and current coastal almanac, such as 'Reeds' or 'Browns'

in NW Europe.......

And on the shore in UK, we have masonry and metal 'Trig Points', of known Lat and Long scattered around the landscape.

Good navigating

Michael Bradley