Ephemerides sive almanach perpetuus

which remains in degrees and minutes, enter the table of hours of conjunction or opposition placed at the end of the lunar Ephemeris. Where that number is found transversely at the top of the table in the front, immediately beneath it, opposite the previously noted distance on the left side, in their common angle, you will see the number of hours and minutes continuously, in which the proposed conjunction or opposition will be accomplished. You can elicit the remaining aspects of the Moon with the Sun in no other way if you wish. If one or more revolutions, as mentioned above, have passed, or if they are of prior or posterior years, the calculation must be performed in the finding of a conjunction or opposition or any aspect in a manner completely opposite to the advice given above regarding extracting the motion of the Moon.

The place of the Moon's head of the dragon will be made clear to you from its Ephemeris if you read the number of signs, degrees, and minutes next to the year representing your proposed year, similarly written around the month and day, all joined together.

However, as often as any revolution of prior years has been transacted, you will subtract 1 degree and 16 minutes from the signs, degrees, and minutes expressed there. If, however, the revolution of years is posterior, you will add; and what results from these will insinuate the motion of the head of the dragon for the proposed day.

By then subtracting the place of this head from the true place of the Moon, the argument of its latitude will result. With it, if you wish to find its latitude, you will easily find it from the table of the Moon's latitude by entering with the signs in the upper or lower part of that table, and beneath the sign found either below or above, opposite the degrees on the left side, ascending or descending according to the exigency of the sign's position, the latitude of the Moon will appear in degrees and minutes in the common angle.

The motion or true place of Venus can be extracted from its Ephemeris in a manner and use similar to that which we taught for finding the Sun's motion, on any day

whenever you please, adding or subtracting nothing, no matter what revolution has passed.

The motion or true place of the remaining planets, namely Mercury, Mars, Jupiter, and Saturn, is known by almost the same path from the Ephemerides of each in this way. Having grasped the year representing your proposed year, which will offer itself most readily to one seeking it transversely at the front of their Ephemerides, soon in the column beneath it on the left side, opposite the proposed month and day, the current motion of any of them will show itself from its Ephemeris, which consists of degrees and minutes; the character placed above first teaches to which sign it belongs. But if the proposed day does not appear in the order of days, since they are not noted as individual days as in the Sun or Moon, etc., but collected, you will consider two neighbors next to it. For by conjecturing proportionally according to its position relative to them, you will estimate the quantity of motion in some way between the two quantities of motion corresponding to those two neighboring days. When any revolution has passed, Saturn and Mars subtract one degree and 16 minutes in prior years, but in posterior years they add the same. Mercury and Jupiter, however, do not require any addition or subtraction in these.

I shall use here, as words of Johannes de Regiomonte Regiomontanus whom I am most delighted to use when it squares with our own. If it pleases you to inquire into the true motion of any luminary or other planet, etc., for any hour of the day: elicit its daily motion, that is, the difference of two immediately written motions; from this, learn the hourly portion, which is the twenty-fourth part of the motion. If you add this as many times to the written motion as there are hours past noon for a planet proceeding forward, or subtract it as many times if it is moving backward, the true motion for the proposed hour will emerge. This use is common for all planets in these.

There is, furthermore, another kind of renumbering