Note also, That this Experiment may be sufficiently Tryed and Proved, by only two or three Voyages, to the South-West parts of Ireland, or to Newfoundland at farthest.
But notwithstanding what has been said, It is chiefly to be noted, That altho’ I have proposed (for Example sake) that the General Numbers should be found, by Sailing to Newfoundland, Virginia, Barbados, &c. and returning again to a Meridian Line at London: Yet if the Honourable Persons before-mentioned in this Title-Page, to whom the whole is most humbly submitted, will please to appoint a Ship for this purpose, the said Numbers may be much better found in manner following; (that is to say) By ordering that the said Ship shall first make a true Meridian Line, at or near the Lat. of 60 Degrees; and thereby set the Movements going, in manner aforesaid: After which let them Sail about 40 or 50 Leagues distant from the Shore, and there Cruise Northward and Southward for about a Month’s time; after which let them return again to the same Line, and find the Numbers, and also enter them, as before directed. And having so done, let them make another Meridian Line, about 15 Deg. more Southward, and there do in like manner: And so at the like Distance to the Equinoctial. After which, let them begin again, and repeat the same Process for three or four times: By which means the Numbers will be found, and the different Motion of the Movement discover’d, for all Latitudes and Seasons, as near as needful.
And being returned home, by these Numbers we may find the true Difference of Motion, in and for the several Latitudes and Seasons. Which Difference must be entred in the 4th Column of the respective Books, reserved for that purpose. By the help of which said Differences, you may make as many Movements as may be needful, at any time; as also Books and Numbers peculiar to each Movement. The Rules for which will be imparted to any such Watchmaker, as may Reasonably desire the same.
FINIS.