very well
we appear to be in complete agreement
so i too will indulge myself a
wish i had done that
also
but in this case i can fulfill the wish immediately
since it has to do with premature rounding off
& i can easily just unround a few things as follows
to begin with
i was in fact a little slack in stating the nad27 conus latitude of
the 1909 idwa marker only to the nearest centisec as
nlat 48d59m57s36
when i could & probably should have been as precise as the
millisec
nlat 48d59m57s357
since that is the apparent level of accuracy in which the coords
were originally stated on the tablet in nad83
this more refined position range
in being stated to the nearest millisec or inch
lies
to the nearest inch
about 3 inches south of the center of the position range that was
previously stated only to the nearest centisec or foot
however
the particular nad83 millisec values given on the tablet happen
to end suspiciously in 5 & 0 respectively
so this could indicate demicentisecs rather than true millisecs
in which case the corrected latitude could be
nlat 48d59m57s3573 plus or minus a semidemicentisec
or in other words
somewhere in the 6 inches that lie between
nlat 48d59m57s355
&
nlat 48d59m57s360
but in the case of either of the above refinements
whether to the 1 inch range or only to the 6 inch range
the improved geoposition for true bcidwa will be centered about
3 inches south of the geoposition that was prematurely rounded
to the 1 foot range
in addition
the ratio of longitude differential that i also previously referred to
actually
12 point 0304414 to one
when applied to the latitude differential
places true bcidwa not exactly 5 full centisecs south of the
latitude of monument 195
as i also recently indicated all too crudely in the geocoords
for that was actually another case of premature rounding off on
my part
rather this ratio places true bcidwa more nearly exactly
4 point 74 centisecs south of the latitude of 195
before rounding
& therefore 1 point 53 centisecs due north of the newly refined
position of 1909
also before rounding
which centers the best guessed linear foot for true bcidwa not
exactly 1 foot due north of 1909
as i also recently stated so confidently
but
by postponing the rounding off until the last possible moment
& carrying the computation out to the nearest inch rather than
merely to the nearest foot
as all the data & the ratio method fully warrant doing in this case
it centers the 1 foot target range of true bcidwa not a crude foot
north of 1909 but fully & more nearly exactly 18 inches north of
1909
therefore
instead of keeping the linear target foot of true bcidwa
between 6 & 18 inches due north of 1909
i can now refine its placement to
between 12 & 24 inches due north of 1909
or
for best guess
18 inches due north of the 1909 disk center
but that is still emphatically plus or minus 6 inches
because regardless of the refinement level of the tablet coords
& regardless of the reliability of the ratio constant
the ibc coords are still stated only to the nearest centisec or foot
--- In
BoundaryPoint@yahoogroups.com, "Dave Patton [DCP]"
<dpatton@c...> wrote:
> At 03:29 PM 2004/08/01, aletheiak wrote:
> > > My photos show the
> > > ridge as seen from both BCIDWA and monument 195, but
> > > I don't know exactly where monument 194 is located, so
> > > it might, for example, be possible to see 195 from 194,
> > > but not see BCIDWA.
> >
> >they are almost always set on the ridge line
> >especially in such remote areas
> >so as to be as visible as possible generally
> >as well as to be intervisible in both directions
> >& thus to require as few monuments as absolutely necessary
> >
> >the topo confirms this too
> >
> >just bushwhacking west along the clearcut from bcidwa might
> >well be the best way to reach 194
>
> No, the best way, at least from the East, would be to follow
> the gravel road past the turnoff I took to get to BCIDWA,
> and along until it ends near the power lines(off the
> right-hand side of my photos, north of the boundary)
> and then walk southwest up the ridge to the boundary.
> The topo map posted along with my confluence visit:
> http://www.confluence.org/photo.php?visitid=8945&pic=13
> shows the power lines as the dashed line, along with
> the gravel road. In retrospect, I wish I had done
> that when I was there, but too late now.
>
>
>
> --
> Dave Patton
> Canadian Coordinator, Degree Confluence Project
> http://www.confluence.org/
> My website: http://members.shaw.ca/davepatton/