Below is the reply sent early this morning by Mr. William S. Schenck of the
Delaware Geological Survey in answer to my inquiry regarding the
under-measurement of the twelve-mile arc at its lower crossing of the Delaware
River.
The figure from the Perry article to which he refers can be found at this direct
link:
http://www.udel.edu/dgs/graphics/IS06FIG2.jpg .
The answer as a whole is not very helpful, but it is suggestive that the
under-measurement is a product of some bizarre projection of the DEPA compound
curve with all of its vicissitudes. I am still of the opinion that the
rationale will be found in the report of the Special Master.
Lowell G. McManus
Leesville, Louisiana, USA
----- Original Message -----
From: "William S. Schenck"
To: "Lowell G. McManus"
Sent: Wednesday, February 16, 2005 7:38 AM
Subject: RE: 12-mile circle in Delaware River
> Mr McManus
>
> I know just enough about the history of the Delaware - Pennsylvania 12-Mile
> Circular Boundary to make me dangerous. I do know that the boundary is
> composed of 2 compound curves, not one arc of a 12-mile circle. The radius
> of both curves constantly increases from west to east. The reason for the
> compound curves is that the 1701 survey of the line had problems with their
> chains getting worn and longer and longer as they progresses from west to
> east. At DE-PA #10 they made a correction and you can actually see that is
> the line today.
>
> The best reference I can direct you to is an article that appeared in the
> journal of Civil Engineering. The reference for it is:
>
> Perry L., 1934, The circular boundary of Delaware, Civil Engineering: v. 4,
> no. 11, p. 576-580.
>
> You can see one of the figures from that article in my information pamphlet
> about Delaware's boundaries on our web site at
> http://www.udel.edu/dgs/Publications/pubsonline/info6.html
>
> That's about all I know.
>
> Regards
> William Schenck
>
>
>> -----Original Message-----
>> From: Lowell G. McManus
>> Sent: Sunday, February 13, 2005 10:20 PM
>> To: William S. Schenck
>> Subject: 12-mile circle in Delaware River
>>
>> Mr. Schenck,
>>
>> I am a researcher into the state and international boundaries
>> of the USA. I have a good understanding of the many
>> complexities of Delaware's boundaries, but there is one that
>> has eluded me thus far. I hope that you can point me in the
>> right direction.
>>
>> In its 1935 decree in New Jersey v. Delaware (295 U.S. 694),
>> the United States Supreme Court specified a radius of
>> "59,764.2 feet" (about 11.32 miles) for that short
>> southeastern arc of the "twelve-mile circle" across
>> Artificial Island in the Delaware River.
>>
>> Why does the decreed radius deviate from the twelve miles
>> specified throughout the history of the boundary?
>>
>> I thank you very much.
>>
>> Lowell G. McManus