the massachusetts town line monument atlases i mentioned
were published by the state board of harbor & land
commissioners in boston & should still at least be available at
the state library in boston too if not in every local library
--- In
BoundaryPoint@yahoogroups.com, "acroorca2002"
<orc@o...> wrote:
> ahh in that case i think what you probably have there is an
older
> undimpled tri town monument
> on which the position of the tripoint can nevertheless still be
> inferred as the center of the top face
> assuming the rock is still fully erect
>
> & it seems this rock has subsequently attracted a disc marker
> from a survey which
> tho its specific purpose is admittedly unclear
> cant just be presumed to trump & displace the center of the
> stone for most authoritative tripoint position
>
> & this even in the teeth of the fact that that center is bare
>
> but more to the point might be to learn what the essex county
> street line per se is
> or what kind of commission attached the disc to the rock
> etc
>
> --- In BoundaryPoint@yahoogroups.com, Michael Kaufman
> <mikekaufman79@y...> wrote:
> > Ok, with my last post in mind...
> > The disc is not at the center of the marker (it is
> > really quite far off from center). Note: the disc
> > says "Essex County Street Line" and no real crosshairs
> > or lines, just a small hole (but not like dimples I've
> > seen on other markers)
> > So would the tp be the center of the marker as seen
> > from above or the center of the disc which is off to
> > one side of the marker?
> > I'll try to post a pic soon to make it easier to
> > visualize...
> >
> > --- acroorca2002 <orc@o...> wrote:
> > > & more likely
> > > & especially in recent centuries
> > > any dimple or crosshairs etc was already scribed at
> > > the exact center
> > > of the monument or disc by the manufacturer
> > > so the surveyor wouldnt have to do this for himself
> > >
> > > --- In BoundaryPoint@yahoogroups.com, "Lowell G.
> > > McManus"
> > > <mcmanus71496@m...> wrote:
> > > > Michael Kaufman asked:
> > > >
> > > > > ...My question is
> > > > > this: Is the exact tripoint
> > > > > 1. the middle of the marker?
> > > > > 2. the county placed disc?
> > > > > 3. the dimple?
> > > > > And HOW would we know? I would assume there
> > > can't be
> > > > > too much official paperwork on 4th-level
> > > boundaries.
> > > > > But maybe some general set of guidelines
> > > somewhere?
> > > >
> > > > The dimple! It was likely put there by the
> > > surveyor using a hammer
> > > and die to
> > > > mark the exact point on the disc where the point
> > > of the plumb bob
> > > hanging from
> > > > his transit came to rest. Any subsequent surveyor
> > > who measures
> > > from the
> > > > monument will center his transit's plumb bob over
> > > the same dimple.
> > > >
> > > > Lowell G. McManus
> > > > Leesville, Louisiana, USA
> > >
> > >
> >
> >
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