( 6 ? 8 )

By tlte liclp os the foregoing Table you will atways know, what a Cloclcu is by the Sun prccilely, and confequently, whether the Watchh h^vc been(et to the' right Meafure of the Mcan Day, or no ; using t;he fable asfollows.

When you first Set your Watch by the Sun, you are to Subduct from theTime observed by the Sun, the JEquation adjoyned to that Day of the Monthin the Table, and to Set the Catches to the remaining Hours, Minutes andSeconds ; that is, the iVatchcs are to be Set (o miich Slower than the Timeof the Sun , as (in the Table) is the JE quation of that Day ; so that the JEqua-tion of the Day Added to the Time of the Clock, is the True Time by theSun. And when aster sorne Days, you delire to know by the Watch the Timeby the Sun, you are to Add to tfce Time fhewed by the Watch , the JEquationof that Day ; and the Aggregate (hall be the Time by the Sun, if the Watchhath been perfectly well Adjusted aster the Meafure of the Me an Days ; forthe doing of which, this will-be a convenient Way ;

Draw a Meridian Line upon a Floor, and then hang two Plummets, eachby a (mali Thread or Wire, directly over the siid Meridian, at the djstancc offorne two Foot or more one from the other, as the lmallneß of the Threadwill admir. When the Middle of the Sun (the Eye being placed (o, as tobring both the Threads into one Line) appears to be in the (ame Line exact-ly, (for the better and more secure discerning whereof, you must be furnilh’dwith a Glaß of a Dark Colour, or somewhat Blackt with the Smoak of aCandle,) you are then immediately to Set the Watch, not prccilely to theHour of ix, but by (b much leß as is the JEquation of that Day ; e. g. If itwere the ixth of March, the JEquation of that Day being by the Table,8'. 3". These are to be Subducted from ix Hours, apd the Remainder wiUbe ii* 1 . zT. qy 11 . to which Hours, Minutes, and Seconds, you are to Setthe Index of the Watch refpectively : Then aster forne Days you afe to ob-ferve again in the sime manner, and likewise to note the Hour, Minute, andSecond of the Watch j to which you are to add the JEquation of these Days,taken out of the Table ; and if the Aggregate do just make ix Hours, theWatch is Adjusted to the Rieht Meafure; but if it differ, you are to Dividethe Minutes and Seconds of that Difference by the Number of the Days be-tween both the Observations to get the Daily Difference.

Lct us fuppofe this Second Observation to have been made the xoth of Marcisvi^. Light Days aster the first, and finding that the Middle of the Sun, beingseen in the Meridian in the fame Line with the two Threads, as beforc,

The Watch Points, ---1 i h . 5V. oy' 1 .

The JEquation of the xoth of March, by the Table, is-00 10 40

Which being Added to the Time, (how'd by the gives-ix 01 47

If this had been just ix Hours, the Watch would have been well adjusted,but being i x . 47". more than ix, it hath gone so much too fast in eightDays. And these i'. 47", that is 107". being divided by 8, there comes1 Seconds for the Difference of every 14 Hours ; which Difference being

known.