The Form of the Book to be kept for each Movement, wherein must be entred the Numbers, &c. (which are to be found at the Returning of the Ship) for finding the Hour and Minute at London.

The Movement, Number 1. was first Set Going Sept. 4. 1714. and Then made one Revolution, in 5 days, 4 hours, and a quarter.
Degrees of Latitude. Numbers to be found and used in finding the Hour at London. Hours spent in producing the said Numbers. Difference in Numbers. Seasons in which the Ship was Sailing. Time when the Movement was set in Motion & Try’d; at & after first Making or Cleaning. Numbers, shewing how the Motion is retarded by Foulness, on a Tryal of 10 Days at a time.
I. II. III. IV. V. VI. VII. Days.
50 29276.2 240 Autumn Sep. 16. 1714 29276.2 10
52 37962.4 432 Winter Dec. 4. 1714 29272.5 10
44 37942.   430 Spring Ma. 20. 1715 29264.   10
48 37912.2 431 Summer June 1. 1715 29237.4 10
Cleansed Sept. 5. 1715. Then made one Revol. in 5 days, 4 ho. and ⅛.
50 29274.2 240 Autumn Sept. 5. 1715 29274.2 10
52 37957.9 432 Winter Dec. 17. 1715 29268.   10
44 37942.   430 Spring Ma. 16. 1715 29264.   10
48 37907.5 431 Summer June 8. 1716 29232.7 10

Note, That the Numbers to be used after Cleaning, (viz. after Sept. 5. 1715.) are found by Substracting or Adding the Difference between the two Numbers in the Seventh Column, (viz. that of Sept. 5.) and that of Sept. 16. (which is only 2.) out of the former Numbers to be used for the same Latitude; on which there will remain 29274.2 for the New Number to be used in Lat. 50. Deg. in Autumn, instead of the former, until the next Cleaning, (which must be only Annually) and so of the rest, from one Cleaning to another. And this method must be used for the respective Latitudes, according as Observations shall be made therein, and Numbers found to answer thereunto.

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.