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.