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
When the world was flat, navigators of sea going ships only needed to have knowledge of how to determine locations in the North-South direction. Following the shore line was a common method of travel. After all, if ships sailed too far to the West, they would fall over the edge!
Latitude and Longitude are astronomic terms used to define the angular distance measured on the surface of the earth. Latitude is in the north-south direction and Longitude is measured in the east-west direction. Both are measured in degrees or in hours, minutes and seconds from a fixed meridian. The subject of this instruction is not to educate you as an astronomer, the terms are defined to set the stage for a history lesson.
By the middle of the sixteenth century there were two established methods of finding Latitude on land or sea. The determination of Longitude was more complex; the solution to it’s determination is the subject of our history lesson.
The need of a simple solution for the determination of Longitude was addressed by the English Parliament in 1714 when they authorized a public reward to a person(s) “who shall discover a simple method for determining Longitude”. Differing rewards were assigned for the accuracy achieved: 10,000 pounds for a device that would determine the Longitude within one degree, 15,000 pounds for an accuracy within 40 minutes and 20,000 pounds for a solution within 30 minutes. A Board of Longitude was appointed to serve as judge for devices or techniques submitted.
For fifty years, this reward stood untouched; it’s solution was conceived to be an impossible task. The Board of Longitude did not meet for several years and had not received a solution worthy of their consideration. The solution to this ‘Longitude’ problem had stumped the best minds of Europe. Most scientists were convinced the solution would come from a system developed using the stars and the heavens. Time keeping device of the day were not capable of accurate time; yet the solution was finally provided by a ticking machine in a box. The work of an uneducated carpenter. John Harrison, developed what is now referred to as “The Marine Chronometer”. A time keeping device made by Christian Huygens had been developed in 1660; Huygen’s clock was controlled by a pendulum and was of little value unless used for sailing in calm waters. Harrison’s clock and solution for the Longitude solution required many new features to convert a clock capable of solving the “impossible” task of keeping accurate time while at sea.
The history behind the development of the ‘Marine Chronometer’ consumed John Harrison’s lifetime and provided many obstacles before his device was accepted. Harrison was born in the parish of Wragby, Yorkshire in May 1693. The son of a carpenter, John spent several years in the profession of his father. He also worked as a surveyor, but developed an interest in clocks; he was self taught and studied mathematics and physics. His interest in clocks resulted the developing improvements which improved the keeping of time. At the young age of twenty-two, he built a grandfather clock, made with wood gears which was capable of an unheard of accuracy.
In his quest to gain this degree of accuracy, Harrison made several improvements to his clocks. He noted that expansion and contraction of the clock pendulum caused clocks to be irregular. Clocks with a common pendulum ran fast in the winter and slow in the summer. Harrison developed the “gridiron pendulum”. Harrison’s pendulum was constructed with alternating lengths of brass and steel penned together in a grid so that their expansion and contraction compensated each other. Because accuracy of a clock is no better than it’s escapement, Harrison devised an improved escapement, called “the grasshopper escapement”, which was was noiseless and nearly friction-less. His grandfather clock, equipped with his pendulum and grasshopper escapement did not gain or lose more than a second a month during a period of fourteen years.
John Harrison was thirty-three years old when he decided to seek the award for a solution to the Longitude quest. A major obstacle in that effort was ”The Board of Longitude”. Harrison was advised that rather than contact the board , he should seek council with the most noted clock maker in London, George Graham. This meeting with Graham resulted in the recommendation that Harrison delay contact with the board until he had completed his clock. Harrison spent the next two tears with this task. His first attempt was a clock which has become known as H1, (or Number One).
Completed in 1735, Number One was not a graceful looking clock. It weighed seventy-two pounds, was housed in a wooden box (3' by 3') and was equipped with gimbals to keep it level. This clock was tested and appeared to satisfy the award requirements; however, Harrison’s clock was not accepted. The board never acknowledged Harrison’s clock as a solution to the Longitude problem.
Harrison;’s struggle with ‘The Board of Longitude’ continued for several years without solution. Meantime Harrison, never accepted defeat and was never satisfied. He went on to complete four additional versions of his clock, H2, H3, H4 & H5, None of these efforts completely satisfied the demands of ‘The Board of Longitude’.
The remaining saga of Harrison’s story is intriguing and includes an association with ‘The King Of England’. Harrison and his son William, did receive the full amount of the award through an act by the ‘English Parliament’. The Board of Longitude never acknowledged that John Harrison’s clock was the solution to the determination of Longitude. The reader is referred to the books ‘Longitude’ by Dava Sobel or ‘Longitude, The Prize’ by Joan Dash.
John Harrison was offered and refused admission to the ‘Royal Society of London’; he was awarded
the “Copley Medal”, the highest honor the Royal Society could bestow. Later, John’s son William did accept admission to the society. It is interesting to note that William never had any further activity in clock making after his fathers death.
The ability to determine Longitude was important to mapping the world. The progress of mapping was important and progress was slow. However, that is another story.
posted May 25, 2020
Almanac Subject Of The Day
The Story of Longitude
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!
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
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
The Story of Standard Time