- No chronometer is expected to keep perfect time.
- But if a chronometer gains or loses the same amount each day (i.e., if it has a constant daily rate),
- Daily rate may change due to temperature variation, vibration, shock, magnetic influence, irregular winding, age, etc.
- It is suitable for navigation because the precise value of the chronometer error at any instant can be obtained by simple extrapolation.
- The chronometer error is noted each day at sea by means of radio time signals and the error noted in the ‘chronometer error book‘
- A chronometer is landed ashore for repairs or overhaul when
- Its daily rate is erratic
- Or the daily rate of a spring tension chronometer exceeds 6 seconds.
History of chronometer
A marine chronometer was a high tech product of its era which can be compared to other landmark inventions like the telegraph, steel making, railways, steamships and so forth. The chronometer was the life work of one man, John Harrison, spanning 31 years of persistent trial and error that revolutionized naval (and later aerial) navigation. The British beat France, Spain, Germany, Holland and Belgium as colonisers of the world because of superiority of the Royal Navy over all other navies. Royal Navy proved to be superior to other navies of the era because they always had a technological edge over the others. The Chronometer was one such invention. British fleets had the surety of navigation given by the chronometer, and their Portuguese, Dutch, and French opponents did not.
