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known, is you want time, or have no mind to take the Pain:>, to Adjust theM'atch to its Right Measure, (this being not ncccstary, st nee you may bringit thus on SLip-Board) note only the Daily Difterence, and regulate your (elfaccordingly. But if you will Adjust it better, you must Remove theleß Weiglit of the Pendulum a little downwards, which will make it goSlower j and then you must begin a-new to oblerve by the Sun , asbefore. If it had gone too Slow, you must have Remov’d the mentionedWcight (omewhat upwards. And this is of that Importance in the fändingout of Longitudes , that if it be not Observcd, you may sometimes in thesoace of Three Months milrcckon 7 Dcgrccs, and more yet, (without anyfault in the M atches ;) which under the Trcpickj will amount to above 400Unglißo Miles.

The ll'atch may be also Adjusted on Board , when a Ship Rides at Anchor,thus : In the Morning, when the Sun is just half above the Horizon, Notewhat Hour, Minute, and Second, the PP'atch points at, if it be g)ing ; ifnot, fet it a going, and put the Indexes at what Hour, Minute, and Secondyou pleale. Let them go till Sun-Set, and when the Body ot the Sun is justhalf under the Horizon, lec what Hour, Minute, and Second, the Indexes ofthe Wdtch point at, and note them too; and reckon, how many Hours, (3c.are pasted by th tlVatcb between the anp and the other. Then take the lialfof that Numher, and Add it to the Hours, ( 3 c. of the Morning Obfervation,and you Ihall have the Hours, &c. which the Wasch did (how, when the Sunwas in the South ; whereunto Add the ALcjuation in the Table belonging to ,that Day, and note the Stirn. Then some Days being paß’d, (the more thebetter,) you are to do just the some : And if the Hour of this last Day be thesome that was noted before, your Watcb is well adjusted ; but if it be moreor leß, the Difference divided by the Number elapsed between the two Ob-fcrvations, will give the Daily Difterence. And if you will, you may let itRest there, or otherwise, Removing the Tester VVeight of the Pendulum youmay Adjust it better. You may also, instead of the Sans Bjfmg and Setting,take two Equal Altitudes of the Sun, before and alter Noon, and having no-ted the time given by the Watcbcs at the time of both the Observations, pro-ceed with it in the sime manner, as was just now directed for Obßrving theSun in the Horizon. In either of which ways there may be some Enour,caused by the Sans RjfraFlion, which is inconsiderable, and therefore needs notto be taken notice of.

5. Give to each of the Matches a Name, or a Mark, as A, B, C; and f 0 find by tbtmbefore you let Sail, sot them to the Time obferved by the Sun in the place ,hr Longitude >where you are, and whence you are departing, allowing for tho SF.quation of atÄ *'the Day whereon you make your Obfervation ; which Day you are to note,if the VVatches be not well adjusted j otherwiso it is not necestary.

Then afterwards being at Sca, and des,ring to know the Longitude of thePlace where you are; that is, How many Degrees the Meridian of that Placeis more Easterly or Westerly, than the Meridian of that Place where you didlet the ffatcl.es ■, you must oblerve by the Sun or Stars, what Time of theDay it is, asprecisely as is polfible, and Note at the some time, to what Hour,

Minute«,