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Boston CPB/Chahy 39
Posted by: Groundspeak Regular Member Shorelander
N 42° 22.552 W 071° 03.709
19T E 330250 N 4693568
Quick Description: A Boston City Planning Board disk near the Bunker Hill Monument in Charlestown.
Location: Massachusetts, United States
Date Posted: 4/4/2006 9:25:57 PM
Waymark Code: WM9XM
Published By: Groundspeak Regular Member seventhings
Views: 12

Long Description:

This mark is part of a First-Order Triangulation network set up for the City of Boston by the WPA from 1935-1941. Information on the location was found in Report on a Geodetic Survey for Boston, 1935-1941 (WPA Project Numbers 65-14-5744, 665-14-3-952, 165-1-14-259), published Nov. 1942.

The network consisted of 65 stations spread throughout Boston, spilling into neighboring municipalities. Many of the stations had local transfer triangles, consisting of one or more disks - this disk is not one of the 65 stations, but a transfer point.

The disk is a transfer point for the station CHAHY. Station CHAHY, if it still exists, sits atop the Schoolhouse on Monument Square condominiums (30 Monument Square; at the time, Charlestown High School).

The aforementioned publication has this to say about the transfer point itself on page 51:

"Ground Transfer Point, 'Chahy', CPB Disc No. 39 - (First order traverse No. B3/0)
Description: This point consists of a C. P. B. disc set in curb on south side of Monument Square near Pleasant Street directly in front of house No. 38 on Monument Square.

The text gives specific measurements, but the area has changed some since 1938, so I will give new measurements. The disk sits near 37-39 Monument Square and is embedded in the curb on the south side of the street. It is 53" from a 16" tree, 100" from a gas cover, and 63" from a second gas cover.

Table II (p. 176) of the book gives the Massachusetts State Lambert Projection Coordinates (based on the C&GS adjustment, 1941) of this station as (718268.31, 501633.28).

Condition: Mark found in good condition

Designation: CHAHY TR39 B3/0

Benchmark Agency: Not listed

Monumentation type: TRAVERSE STATION Disk

County: Suffolk

USGS 7.5' Topographic Quadrangle Name (optional): Boston North

Find type: Found by luck/skill/knowledge

Benchmark Agency (if other): Not listed

Monumentation type (if other): Not listed

Special category (optional): Not listed

Special Category (if other): Not listed

Web address of this benchmark's datasheet (optional): Not listed

NGS PID: Not listed

Local database's URL (optional): Not listed

Visit Instructions:
  1. A closeup photo of the mark taken by you is required.
  2. A 'distant' photo including the mark in the view is highly recommended. Include the compass direction you faced when you took the picture.
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Shorelander visited Boston CPB/Chahy 39 4/2/2006 Shorelander visited it

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