Robison to his father begins; and though the letters do not enter much into particulars, they leave us less at a loss about the remaining part of his seafaring life.

On the 3d of August the Royal William returned to Plymouth, the greater part of the crew being totally disabled by the sea-scurvy, from which Mr Robison himself had suffered very severely. He writes to his father, that, out of seven hundred and fifty able seamen, two hundred and eighty-six were confined to their hammocks, in the most deplorable state of sickness and debility, while one hundred and forty of the rest were unable to do more than walk on deck. This circumstance strongly marks, to us, who have lately witnessed the exertions of British sailors, in the blockade of Brest, and other ports of the enemy, the improvement made in the art of preserving the health of seamen within the last fifty years. The Royal William, notwithstanding the state of extreme distress to which her crew was reduced, by a continuance at sea, of hardly six months, was under the command of Captain Hugh Pigott, one of the most skilful officers of the British navy. Mr Robison, indeed, never at any time mentioned his name without praise, for his knowledge of seamanship, and the address with which he used to work the ship, in such bad weather, as rendered her almost unmanageable to the other officers. The art of preserving the health of the seaman is a branch of nautical science, which had at that time been little cultivated. Our great Circumnavigator had not yet shown, that a ship's crew may sail round the globe, with less mortality than was to be expected in the same number of men, living for an equal period in the most healthful village of their native country.

Mr Robison's letters to his father, about this time, are strongly expressive of his dislike to the sea, and of his resolution to return to Glasgow, and to resume his studies, particularly that of theology, with a view of entering into the church. These resolutions, however, were for the present suspended, by a very kind invitation from Admiral Knowles, to come and live with him in the country, and to assist him in his experiments; "Thus, (says the admiral,) we shall be useful to one another." What these experiments were is not mentioned, but they probably related to ship-building, a subject which the admiral had studied with great attention. Mr Robison, accordingly, continued to enjoy a situation, and an employment, that must both have been extremely agreeable to him, till the month of February in the year following, when Lieutenant Knowles was appointed to the command of the Peregrine sloop of war, of 20 guns. Whether the plan of nautical instruction which Mr Robison proposed for his pupil was not yet completed, or whether he had, after all, come to a resolution

of pursuing a seafaring life, (of which there is an appearance in some of his letters,) he embarked in the Peregrine, and he even mentions his hopes of being made purser to that ship. The first service in which Captain Knowles was employed, was to convoy the fleet to Lisbon. In a letter from Plymouth, where they were forced in by the weather, Mr Robison paints, in strong colours, the difference between sailing in a small ship, like the Peregrine, and a first rate, like the Royal William, and the uncomfortable situation of all on board, during a gale which they had experienced in coming down the Channel. The voyage, however, gave him an opportunity of visiting Lisbon, on which the traces of the earthquake were yet deeply imprinted; and the ship continuing to cruize off the coast of Spain and Portugal, he had occasion to land at Oporto, and other places on the Portuguese coast. In the month of June he returned to England; and from this time quitted the navy, though he did not give up hopes of preferment. He returned to live with Admiral Knowles, and in the end of the same summer, was recommended by him to Lord Anson, the First Lord of the Admiralty, as a proper person to take charge of Harrison's time-keeper, which, at the desire of the Board of Longitude, was to be sent, on a trial voyage, to the West Indies.

The ingenious artist just named had begun the construction of his chronometer, on new principles, as early as the year 1726, and with the fortitude and patience characteristic of genius, had for thirtyfive years struggled against the physical difficulties of his undertaking, and the still more discouraging obstacles which the prejudice, the envy, or the indifference of his contemporaries, seldom fail to plant in the way of an inventor. Notwithstanding all these, he had advanced constantly from one degree of perfection to another, and it was his fourth time-keeper, reduced to a portable size, and improved in all other respects, that was now submitted to examination. It was intended that Mr Robison should accompany young Harrison and the timekeeper, in a frigate, the Deptford, to Port Royal in Jamaica, in order to determine, on their landing, the difference of time, as given by the watch, and as found by astronomical observation. The timekeeper, accordingly, was put into the hands of Mr Robertson of the Naval School at Portsmouth, who determined its rate, from nine days that it remained in his custody, to be 23" slow per day, and also, the error to be 3" slow on the 6th of November at noon, according to mean solar time.

The Deptford sailed on the 18th of November, and arrived at Port Royal on the 19th of January; on the 26th, Mr Robison observed the time of noon, and found it to answer to 4h 59' 7" by the watch, and this being corrected for the error of three seconds, and also for the daily accumulation of 24" for eighty-one days five hours, the interval between the observations, the difference of longitude between Portsmouth and Port Royal came out 5h. 2' 47", only four seconds less than it was known to be from other observations.

The instructions of the Board farther required, that, as soon as an opportunity could be found, the same two gentlemen should return with the watch to Portsmouth, that, by a comparison of it with the time there, the total error, during both voyages, might be ascertained. The opportunity of return occurred sooner than they had any reason to expect; for the Spanish war having now broke out, an alarm of an invasion of Jamaica from St Domingo, occasioned the governor to dispatch the Merlin sloop of war to England, to give intelligence of the danger. Mr Robison and Mr Harrison obtained leave to return in the Merlin, and sailed on the 28th, having been but a few days in Jamaica. This voyage was an epitome of all the disasters, short of shipwreck, to which seafaring men are exposed. They experienced a continuation of the most tempestuous weather, and the most contrary winds, from the moment they quitted the Bahamas, till they arrived at Spithead. To add to their distress, the ship sprung a great leak, three hundred leagues from any land, and it required the utmost skill and exertion to keep her from sinking. In a