Bi Metallic Strip In The H 3 example essay topic

Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time is written by Data Sobel. The book is called Longitude because it is about a clock maker who was able to determine longitude. Determining longitude was the superlative scientific question in the eighteenth century that Galileo and Newton were not able to resolve. The principal inspiration behind the invention completed in this book is that many sailors were lost at seas as a result of their ignorance regarding longitude. So, without the competence to determine longitude, many innocent lives were disintegrated at seas.

England's Parliament was desperate for an answer to this problem. So, in 1714 England's Parliament offered 20,000 pounds to anyone who invented a method or a device for measuring longitude and then proved successful. As a result, a Frenchman, si eur de St. Pierre, frowned on the moons of Jupiter as means of determining longitude. He theorized that longitude could be found by the position of the moon and select stars. At the time, Dr. Edmond Halley proved this theory wrong.

After many observations, Halley concluded that the moon's rate of revolution around the earth was accelerating overtime. John Harrison was a simple clockmaker and a self-educated person who was accredited for finding longitude by means of a timekeeper. John built his first pendulum watch in 1713. It was constructed entirely out of wood. Harrison called his first sea clock Harrison's No. 1 or H-1 for short.

H-1 was bar-shaped, built out of shinny brass, and was big in size. His second attempt was called H-2. H-2 was a heavy weight of 86 pounds, but fitted into a small box as John promised it would. H-2 was also bar-shaped and included an implement to ensure a unchanging drive and a more agreeable temperature reimbursement device. Although its motion was adequately regular and exact for finding the longitude of a ship within the nearest limits proposed by the Parliament, H-2 was not good enough for Harrison. So, Harrison devoted nineteen years to build H-3.

The H-3 was the leanest of the sea clocks and was small enough to meet the definition of 'shipshape. ' ; H-3 contained bearings in the caged ball that smoothened the operation with moving parts. Unlike H-1 and H-2, H-3 ran on two large circular balances wheels linked by metal ribbons. In addition, it was controlled by a single spiral spring.

Furthermore, Harrison introduced a bi-metallic strip in the H-3. The bi-metallic strip compensates immediately and automatically for any changes in temperature that could effect the clock's going rate. But after the H-3 was completed Harrison realized that a small watch might be the greatest device to figure out the longitude. As a result, John Harrison completed H-4 in 1759. It was very minute for a sea clock, and weighed only three pounds. It had two silver cases and a 'genteel white face that showed off four fanciful repeats of a fruit-and-foliage motif drawn in black.

These patterns ring the dial of Roman numeral hours and Arabic seconds, where three blue-steel hands point to the correct time. ' ; H-4 was a watch that embodied the gist of grace and correctness. When Maskelyne tested H-4 it failed the test. Harrison, then, raised many questions and complains about the test and the testers of the H-4.

For example, he said that the men, who were supposed to witness Maskelyne's daily interactions with the watch were not fit for active duty, were too old, and wheezy to climb the steep hill up to the observatory. After H-4 was tested, Harrison asked the Board of London for the watch, but the Board would not return the H-4 back to John. As a result, Harrison completed H-5. H-5 had all the internal complexity of H-4 but presumed an uneven outward appearance. At first, when this watch was tested it failed, but the king extended the period of trial and H-5 proved to be successful. Jeremy Thacker of Beverly, England developed a device to find longitude 'in the sound of cannon blasts, in compass needles heated by fire, in the moon's motion, in the sun's elevation.

Thacker developed a new clock established in a vacuum. Thacker called the device Chronometer. This timekeeping instrument had two special features. First, it was glass sealed. Second, inside the glass there was a vacuum chamber.

Even though the vacuum chamber provided insulation against the effects of heat and cold, it did not display perfection. For instance, it did not adjust to temperature. The difference between the new invention and previous attempts the clock (ancient) was not as accurate as the chronometer. The timekeeping of the clock was affected by weather, humidity, temperature, etc... For example, if the temperature was hot the metal expands and if the temperature is cold the metal shrinks. On the other hand, the chronometer was glass protected and vacuum-sealed which made the device invulnerable to temperature.

In conclusion, the problem of determining longitude was solved after forty years. As I have mention before, John Harrison was awarded the longitude prized for his five inventions..