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7. and 8. To the second argument of latitude add and substracttlie mean anomaly of the Sun, and the seventh and eighth argumentsof latitude will be found.

9. and io. To the second argument of latitude add and substractthe mean anomaly of the Moon, and the ninth and tenth argumentsof latitude will be had.

11. Substract the mean anomaly of the Moon from the tenth ar-gument of latitude, the remainder is the eleventh and last argument oflatitude.

12. With the arguments thus found, take out the eleven equationsof latitude, with their proper signs, from the tables, p. lxv—lxviii,and take the sum of thofe which are affirmative, and also the sum of-thofe which are negative; then take the difference of the sums, withthe fign of the greater, which will be the true latitude of the Moon;and will be north, if marked with the affirmative sign + ; but south»,if marked with the negative fign —.

See the example of calculating the Moon’s longitude and latitudeby Probi. XIV. and XV. annexed at the end of Probi. XV. in the.;Latin precepts, p. 71.

The foregoing precepts and example of calculation are made con-formable to the tities prefixed to the feveral tables, and to the form >.of the example of calculation, p. 39. deduced by the author him-self from the former manuscript tables; but it fhould be obferved, that, .on account of the difference between the prefent tables and thofe, theexample of calculation here given, tho' it apprcaehes near to, yetdoes not perfectly agree with Mayer 's example. So far thereforeIhave only endeavoured faithfully to reprefent the author’s meaning,,as I collected it from his own works. But it will be more convenient -in practice to derive some of the arguments in a method somewhatdifferent from that given above, and to carry on the latter part of the

I, i calculationi