SUBJECTS OF SPECIAL INTEREST
Career Opportunity Engineering and/or Surveying
Presidents Who Were Land Surveyors
Republic of Texas Boundary Survey of 1841
History of Marion County, Texas
History of Jefferson, Texas
CLOCKS OR HOROLOGY
TimeLine of Time Measurement History
Major American Clock Makers
Rotation of the Earth
Latitude, Longitude & Time
American Time Zone
Time Zones Around the World
The American Meridian
The Story of Longitude
The Gregorian Calendar
The Calendar Clock
The Industrial Revolution (Kitchen Clock)
The Clock and Compass Face
Brief Summary of an Almanac Subject
LIST OF ALMANAC SUBJECTS
THE AMERICAN MERIDIAN
Lines used to define direction and relate the shape of the globe we refer to as Earth are named 'Latitude & Longitude'.
Lines of Latitude divide the globe from the South Pole to the North Pole. We define this direction as north & south. Latitude is discussed in another paper which explains Time Zones and is excluded from this writing.
Lines of Longitude divide the globe in the east & west directions. In order to have meaning, a reference point or a point of beginning must be defined. The "Greenwich Meridian", located in England has been adopted as this point.
The Prime Meridian, Royal Observatory, Greenwich England
Prior to acceptance of the Prime Meridian being in Greenwich, the United States and other nations used their own reference for the beginning of their Longitude. "The American Mederian" used until the early 1900's, was defined to be "a line which passed through the center of the original dome atop the main building of the Old National Observatory". It was not until 1916 that the United States implemented the Greenwich standard. To illustrate this difference refer to maps printed prior to 1916. Examples of this situation are included on maps contained in the museum map collection. For example, a map by Asher & Adams dated 1874 shows both the Greenwich and the Washington D.C. longitude. There is a difference of 77 degrees between the two systems.
The average person will be aware of 'Lines of Longitude' when using a globe of earth. Longitude has little application except to define a location for the beginning and end of each day. Longitude is important in navigation, The "Story of Longitude" is interesting and will be published on this site in the future.
'Lines of Longitude' are used to define "Time Zones"around the globe. 'Lines of Longitude' are used to define locations east & west of Greenwich for the time of day. Directions east of Greenwich are defined as positive and time is increasing. To obtain the time for locations west of Greenwich ; it is necessary to add time to the Greenwich time. Directions west of Greenwich are negative and represent the end of the previous day. This application of Time is addressed in a paper titled "The relationship of Latitude , Longitude and Time" and will be published on the site at a later date.
Plan a visit to the Museum of Measurement and Time on your next trip to Texas
History of Land Ownership
History of Measurement & Measurement Devices
Land Surveying Units
History of the Odometer
The Gunter Chain
Napier's Rods & Bone
The Slide Rule
Tidbits of Math
Snippets of Math
The Museum's effort to preserve the history of American Clocks and items which measure includes a compilation of short articles which address items featured in the museum.
To continue this endeavor, the museum provides handouts of this information for museum visitors. The list included below is an example of some of the subjects which have been addressed. The articles are provided to assist in the explaination of items included in the museum. They are not intended to provide a detailed study of the subject. Visitors may obtain a copy of most of this information during their visit to the museum. This information is not copyrighted; however, some subjects and information contained in the articles may be protected by separate copyright. It is recommended that use of the information be for personal use. Copies of this information are not be distributed without specific authorization from the Museum of Measurement and Time.
A list of almanac subjects is provided below. Copies are available when you visit the museum. Please make your request for specific information upon arrival. For persons unable to visit the museum, written requests will be addressed on an individual basis.
This information is featured below and will be changed periodically. Visit us often for the updates!