Notes from Fast Sailing Ships
I. British Shipyards could build the smaller ships, but they were most associated with building large naval vessels.
A. HMS Victory -- 3 decked flagship of the fleet of "wooden walls"
Ordered in 1758 by Pitt the Elder
Built at Chatham Dockyard, the most important dockyard in the Age of Sail.
designed to carry at least 100 guns.
keel was laid on 23 July 1759 in the Old Single Dock
150 workmen were assigned to construct Victory's frame. Another 850 would be involved in the rest of the build.
6,000 trees were used in her construction, of which 90% were oak and the remainder elm, pine and fir; hull was 300,000 cubic feet of timber weighing 3 to 4,000 tones
wood of the hull was held in place by six-foot copper bolts, supported by treenails for the smaller fittings.
Once the ship's frame had been built, it was normal to cover it up and leave it for several months to allow the wood to dry out or "season". The end of the Seven Years' War meant that Victory remained in this condition for nearly three years, which helped her subsequent longevity.
Work restarted in autumn 1763 and she was floated on 7 May 1765, having cost £63,176 and 3 shillings,[ the equivalent of £8.7 million today
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Samuel Pepyes naval reforms. Meritocracy and math exams administered to all would be officers. Pepyes also ended the corruption and graft of the navy's supply system.
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Development of Navigational Science in Britain is all about practical exploitation of the sea.
Royal Observatory --
The problem of longitude — where you are on the planet, east-west speaking — was the thorniest puzzle of the day, or really, of the 18th century. The way southwest from Great Britain to where the riches of the New World lay was really to go south to the correct latitude, which one could easily determine by observing the North Star, then head west until the guy in the crow’s nest yelled, “Land Ho!” Not really efficient.
Thus, in 1714, the British government offered the huge prize of £20,000 (roughly £2 million today) to anyone who could solve the longitude problem once and for all. The competition was to be overseen by a newly created Board of Longitude.
All manner of candidate solutions appeared: lunar tables, complex equations based on the sightings of the planets, and many more. The real solution, everybody knew, was to know the precise time where you were on the open ocean and also know the precise time at home. Then it was a simple calculation to figure out how far west — or east — you were.
Harris, 1759, H4
H1, H2, and H3 were fairly large clocks, ranging in height from 59 centimeters to 66 centimeters (roughly 23-¼-inches to 26-inches) high. Importantly, Harrison’s clocks needed no oil for lubrication. Instead, he designed roller bearings for contact surfaces.
Harrison built H1 between 1730 and 1735. It was essentially a portable version of his wooden clocks, though it was bigger and with several revolutionary improvements to increase precision. H1 proved promising on its trial run to Lisbon, Portugal in 1736; it wasn’t good enough to win the prize, but was encouraging to both Harrison and the Board of Longitude.
Harrison built H2 between 1737 and 1739. H2’s contribution to horology was the remontoir, a device designed to take the variability of the parts manufacturing process out of the timekeeping equation. However, H2 had other problems, and rather than chase his tail trying to fix them, Harrison abandoned H2 and set about building a third timekeeper.
H3 was to prove a major trial for Harrison. At over 700 parts, and subsystems for temperature compensation, a remontoir, and an isochroniser (a device to ensure the clock’s balance wheel swings each way in the same amount of time), the clock was too complex and idiosyncratic to ever work properly. Harrison labored for 19 years before abandoning H3 as the solution to longitude.
Here’s where the story gets interesting. In 1753, Harrison ordered a pocket watch from a London watchmaker. The watch was to be based on Harrison’s own design ideas. When he received the watch, he realized that with certain improvements, it could become the timekeeping answer to the longitude problem. His simple breakthrough discovery was that small, high-frequency oscillators (balance wheels) were much more stable during movement than were larger clocks.
H4, just 13 centimeters in diameter, was the result of this realization. The improvements Harrison made included a balance wheel that was much larger than a typical pocket watch. It oscillated at a higher frequency, five times a second — or 18,000 beats per hour. The watch contained a refined version of the temperature compensation Harrison had included in H3, and it contained a miniaturized remontoir.
The one problem, if it could be called that, was that H4 needed oiling. However, Harrison followed a relatively new practice in friction reduction and installed jeweled bearings in several places to minimize friction.
H4, just 13 centimeters in diameter, was the result of this realization. The improvements Harrison made included a balance wheel that was much larger than a typical pocket watch. It oscillated at a higher frequency, five times a second — or 18,000 beats per hour. The watch contained a refined version of the temperature compensation Harrison had included in H3, and it contained a miniaturized remontoir.
The one problem, if it could be called that, was that H4 needed oiling. However, Harrison followed a relatively new practice in friction reduction and installed jeweled bearings in several places to minimize friction.
This first watch took six years to construct, following which the Board of Longitude determined to trial it on a voyage from Portsmouth to Kingston, Jamaica. For this purpose it was placed aboard the 50-gun HMS Deptford, which set sail from Portsmouth on 18 November 1761.[18]:13–14 Harrison, by then 68 years old, sent it on this transatlantic trial in the care of his son, William. The watch was tested before departure by Robertson, Master of the Academy at Portsmouth, who reported that on 6 November 1761 at noon it was 3 seconds slow, having lost 24 seconds in 9 days on mean solar time. The daily rate of the watch was therefore fixed as losing 24/9 seconds per day.[19]
When Deptford reached its destination, after correction for the initial error of 3 seconds and accumulated loss of 3 minutes 36.5 seconds at the daily rate over the 81 days and 5 hours of the voyage,[19] the watch was found to be 5 seconds slow compared to the known longitude of Kingston, corresponding to an error in longitude of 1.25 minutes, or approximately one nautical mile.[15]:56 William Harrison returned aboard the 14-gun HMS Merlin, reaching England on 26 March 1762 to report the successful outcome of the experiment.[18] Harrison senior thereupon waited for the £20,000 prize, but the Board were persuaded that the accuracy could have been just luck and demanded another trial. The board were also not convinced that a timekeeper which took six years to construct met the test of practicality required by the Longitude Act. The Harrisons were outraged and demanded their prize, a matter that eventually worked its way to Parliament, which offered £5,000 for the design. The Harrisons refused but were eventually obliged to make another trip to Bridgetown on the island of Barbados to settle the matter.
At the time of this second trial, another method for measuring longitude was ready for testing: the Method of Lunar Distances. The moon moves fast enough, some thirteen degrees a day, to easily measure the movement from day to day. By comparing the angle between the moon and the sun for the day one left for Britain, the "proper position" (how it would appear in Greenwich, England, at that specific time) of the moon could be calculated. By comparing this with the angle of the moon over the horizon, the longitude could be calculated.
During Harrison's second trial of his 'sea watch' (H4) the Reverend Nevil Maskelyne was asked to accompany HMS Tartar and test the Lunar Distances system. Once again the watch proved extremely accurate, keeping time to within 39 seconds, corresponding to an error in the longitude of Bridgetown of less than 10 miles (16 km).[15]:60 Maskelyne's measures were also fairly good, at 30 miles (48 km), but required considerable work and calculation in order to use. At a meeting of the Board in 1765 the results were presented, but they again attributed the accuracy of the measurements to luck. Once again the matter reached Parliament, which offered £10,000 in advance and the other half once he turned over the design to other watchmakers to duplicate.[20] In the meantime Harrison's watch would have to be turned over to the Astronomer Royal for long-term on-land testing.
Unfortunately, Nevil Maskelyne had been appointed Astronomer Royal on his return from Barbados, and was therefore also placed on the Board of Longitude. He returned a report of the watch that was negative, claiming that its "going rate" (the amount of time it gained or lost per day) was due to inaccuracies cancelling themselves out, and refused to allow it to be factored out when measuring longitude. Consequently, this first Marine Watch of Harrison's failed the needs of the Board despite the fact that it had succeeded in two previous trials.
In total, Harrison received £23,065 for his work on chronometers. He received £4,315 in increments from the Board of Longitude for his work, £10,000 as an interim payment for H4 in 1765 and £8,750 from Parliament in 1773.[21] This gave him a reasonable income for most of his life (equivalent to roughly £450,000 per year in 2007, though all his costs, such as materials and subcontracting work to other horologists, had to come out of this). He became the equivalent of a multi-millionaire (in today's terms) in the final decade of his life.Harrison began working on his second 'sea watch' (H5) while testing was conducted on the first, which Harrison felt was being held hostage by the Board. After three years he had had enough; Harrison felt "extremely ill used by the gentlemen who I might have expected better treatment from" and decided to enlist the aid of King George III. He obtained an audience with the King, who was extremely annoyed with the Board. King George tested the watch No.2 (H5) himself at the palace and after ten weeks of daily observations between May and July in 1772, found it to be accurate to within one third of one second per day. King George then advised Harrison to petition Parliament for the full prize after threatening to appear in person to dress them down. Finally in 1773, when he was 80 years old, Harrison received a monetary award in the amount of £8,750 from Parliament for his achievements, but he never received the official award (which was never awarded to anyone). He was to survive for just three more years.
Captain James Cook used K1, a copy of H4, on his second and third voyages, having used the lunar distance method on his first voyage.[22] K1 was made by Larcum Kendall, who had been apprenticed to John Jefferys. Cook's log is full of praise for the watch and the charts of the southern Pacific Ocean he made with its use were remarkably accurate. K2 was loaned to Lieutenant William Bligh, commander of HMS Bounty but it was retained by Fletcher Christian following the infamous mutiny. It was not recovered from Pitcairn Island until 1808 when it was given to Captain Folger, and then passed through several hands before reaching the National Maritime Museum in London.
Initially, the cost of these chronometers was quite high (roughly 30% of a ship's cost). However, over time, the costs dropped to between £25 and £100 (half a year's to two years' salary for a skilled worker) in the early 19th century.[23][24] Many historians point to relatively low production volumes over time as evidence that the chronometers were not widely used. However, Landes[23] points out that the chronometers lasted for decades and did not need to be replaced frequently – indeed the number of makers of marine chronometers reduced over time due to the ease in supplying the demand even as the merchant marine expanded.[25][26] Also, many merchant mariners would make do with a deck chronometer at half the price. These were not as accurate as the boxed marine chronometer but were adequate for many. While the Lunar Distances method would complement and rival the marine chronometer initially, the chronometer would overtake it in the 19th century.
| François Marie Arouet de Voltaire (1694–1778). Letters on the English. The Harvard Classics. 1909–14. |
| Letter X—On Trade |
| AS trade enriched the citizens in England, so it contributed to their freedom, and this freedom on the other side extended their commerce, whence arose the grandeur of the State. Trade raised by insensible degrees the naval power, which gives the English a superiority over the seas, and they now are masters of very near two hundred ships of war. Posterity will very probably be surprised to hear that an island whose only produce is a little lead, tin, fuller’s-earth, and coarse wool, should become so powerful by its commerce, as to be able to send, in 1723, three fleets at the same time to three different and far distanced parts of the globe. . . . |
