Cadastral Consulting, LLC

         Quality Continuing Education for the Surveying, Land Use, and Design Professional

• Links to Cadastral Sites
• Free Cadastral Resource Downloads
• The 200th Anniversary of the US Coast and Geodetic Survey, and the Disboro Monument
• Guide to Tidal Datums

BLM Cadastral Home Page

2009 BLM Manual and Errata
(The 1973, 1947, 1890, and 1855 Manuals are available from our Bookstore)

BLM Glossary of Surveying and Mapping terms

Map of Principal Meridians

Jerry Wahl's “cadastral.com”

“The American Surveyor” magazine

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The Land Ordinance of 1785

Standards and Guidelines for Cadastral Surveys Using Global Positioning System Methods, Version 1.0, May 2001 (PDF. 184 KB)

Corner Identification and Markings from the BLM 1973 Manual of Instructions (PDF, 2.2 MB)

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In the early days of our nation, there were no good maps of the coastline for navigators or the militia to use. In 1795, Congress wrote a resolution requesting that President Jefferson authorize a survey to map the New York–New Jersey coast. This map would reduce the number of shipwrecks and benefit the military in planning defense. The resolution authorizing this first coastal survey passed in 1807, but the work did not begin until 1816.

A Swiss–born geodesist and methematican, Fedinand Rudolph Hassler, was named the first superinendant of this US Coastal Survey. He set up a system of triangulation to ensure that the edges of any charted location would align with the edges of adjacent areas. This new system of coordinated surveys became the first US Coast and Geodetic Survey of the domestic waters of our nation.

Hassler's triangulation network stretched from New York City to Philadelphia and consisted of 18 coordinated points, a system later expanded to cover the entire country as it exists today. In 1839, a ceramic cone was buried on Disboro Hill in Millstone Township, Monmouth County, NJ, as a monumented control point in this system.

Here are two articles on the story of that first survey, and of the recovery of the cone at Disboro Hill more than fifty years after it was believed to be lost.

Triangulation Station Disboro 1839; Recovery 1982 (PDF, 688 KB)

Uncovering the Disboro Cone (PDF, 1.7 MB)

Visit our Publications page for information on the documentary video on DVD.

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In 1988, noted oceanographer Steacy Hicks created a light-hearted explanation of tides, featuring “an obscure physical oceanographer”, a “great hydrographer”, and an “intrepid surveyor”. The adventures of these characters and the clarity and factual nature of the text should help even the most reluctant reader understand the concepts of tidal datums.

Thanks to Jeff Olsen of NGS for identifying the “Obscure Physical Oceanographer entombed in the Ocean (Tides) and Lake Levels Division of the Office of Ocean and Earth Sciences of the National Ocean Service of the National Oceanic and Atmospheric Administration of the U.S. Department of Commerce” (as Hicks described himself) as the author of this excellent guide!

Click here to download a PDF file of “Fantastic Tidal Datums” (PDF, 4.4 MB)
or visit the Popular Publications page of NOAA by clicking here for this and other useful resources.

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