to which so many years so laudably and so diligently spent
in the improvement of those talents which God Almighty has bestowed
upon you, will so justly entitle your constant and unwearied
perseverance."

Mr. Folkes, in his speech, spoke of Mr. Harrison as "one of the most
modest persons he had ever known. In speaking," he continued, "of his
own performances, he has assured me that, from the immense number of
diligent and accurate experiments he has made, and from the severe
tests to which he has in many ways put his instrument, he expects he
shall be able with sufficient certainty, through all the greatest
variety of seasons and the most irregular motions of the sea, to keep
time constantly, without the variation of so much as three seconds in a
week,--a degree of exactness that is astonishing and even stupendous,
considering the immense number of difficulties, and those of very
different sorts, which the author of these inventions must have had to
encounter and struggle withal."

Although it is common enough now to make first-rate
chronometers--sufficient to determine the longitude with almost perfect
accuracy in every clime of the world--it was very different at that
time, when Harrison was occupied with his laborious experiments.
Although he considered his third machine to be the ne plus ultra of
scientific mechanism, he nevertheless proceeded to construct a fourth
timepiece, in the form of a pocket watch about five inches in diameter.
He found the principles which he had adopted in his larger machines
applied equally well in the smaller, and the performances of the last
surpassed his utmost expectations. But in the meantime, as his third
timekeeper was, in his opinion, sufficient to supply the requirements
of the Board of Longitude as respected the highest reward offered, he
applied to the Commissioners for leave to try that instrument on board
a royal ship to some port in the West Indies, as directed by the
statute of Queen Anne.

Though Harrison's third timekeeper was finished about the year 1758, it
was not until March 12, 1761, that he received orders for his son
William to proceed to Portsmouth, and go on board the Dorsetshire
man-of-war, to proceed to Jamaica. But another tedious delay occurred.
The ship was ordered elsewhere, and William Harrison, after remaining
five months at Portsmouth, returned to London. By this time, John
Harrison had finished his fourth timepiece--the small one, in the form
of