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
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
LATITUDE, LONGITUDE AND TIME
To understand these termswe need to consider the earth as a sphere or a globe. This globe is divided in two directions, up-down and left-right. The up-down direction is defined to be north-south and is called LATITUDE. The left-right direction is east-west and is defined as LONGITUDE.
To provide meaning to this system, we use the center of earth's globe: defined as the Equator, lines are extended from the equator to the peak of the globe in each direction. We call these ending points as the north & south poles. These lines are called LINES OF LATITUDE.
Dividing a line along the equator into 360 equal segments results in a method to define the location for points on the surface of earth's globe. To complete this system we establish a series of parallel lines from the equator toward each of the pole's. We call this system of lines LINES OF LONGITUDE. To have meaning this system must have one other definition - A Place of Beginning.
The earth is spinning from east to west as it revolves around the sun. This spinning and the tilt of our globe has two effects - one is what we call DAY & NIGHT and the other, our seasons, WINTER & SUMMER. When we define a period of time for each revolution as a basis of time, we have established a method for tracking the passage of time. One complete revolution of earth is called a 24 HOUR DAY.
Tracking the passage of time requires a beginning point. This common point is located on a Line of Longitude and is called the ZERO MERIDIAN. As expected, this point has not always been at the same location for all nations.
The United States, prior to 1900, defined their ZERO MERIDIAN to be in Washington D.C.. Details of this subject is addressed in another paper. The need to adopt a fixed location is oblivious and that location was fixed at GREENWICH, ENGLAND.
With time beginning at this location, a point halfway around the globe became known as the INTERNATIONAL DATE LINE. Points located west of Greenwich are called to be in the negative direction, points located are positive. Thus, when west of Greenwich, time is subtracted from GREENWICH TIME. Points east of Greenwich must adjust their time as an addition to GREENWICH TIME. When crossing the INTERNATIONAL DATE LINE, the date must be adjusted by 24 hours; this change, of course depends on your direction of travel.
The increments of time around the globe is defined into segments called TIME ZONES. This is addressed in another paper.
We hope you agree with this attempt to simplify a complicated subject. We consider all comments as constructive. We appreciate any comments you have concerning our effort.
WE HOPE TO MEET YOU IN JEFFERSON, TEXAS
LIST OF ALMANAC SUBJECTS
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!