Longitude rewards
Parliament grants John Harrison a special £8,750 award
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1773: £8,750, voted by Parliament
In 1773, following Harrison's appeals and a successful royal trial of his fifth timekeeper, Parliament granted him a special award of £8,750 for his services to navigation.
Sources disagree on the exact June date — scholarly payment tables give 19 June, other histories say Parliament agreed on 30 June. The year itself is secure.
Compensation, not the prize
The money was parliamentary compensation rather than an award of the Longitude Prize by the Board of Longitude. Harrison never formally received the reward specified by the 1714 Act, whose three accuracy thresholds offered £10,000, £15,000 and £20,000.
Nor had it ever arrived as one sum. The 1773 grant was his final large payment after decades of development grants and an earlier £10,000 associated with H4; one scholarly accounting totals £23,065 across his career.
What the quarrel was actually about
The Board accepted that H4 met the Act's strictest accuracy limit, then required Harrison to disclose its construction and demonstrate that other makers could reproduce it. That condition, set against his wish to protect his methods, kept the dispute alive.
It outlasted even H5's successful test at the royal observatory at Richmond, which George III supported. Harrison was about eighty when Parliament voted him the £8,750.
Sources
Researched 23 Aug 2026 4 sources 2 audit passes
How this was checked
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What the sources leave uncertain
- Sources disagree on the precise June date attached to the 1773 grant or payment: scholarly payment tables give 19 June, while other histories say Parliament agreed on 30 June. The listed event specifies only the year, which is secure.
- Whether Harrison morally “won” the prize is a matter of interpretation; institutionally, the £8,750 was a separate parliamentary award rather than the Board’s formal £20,000 prize.