Again, Months are not only Lunary, and measured by the Moon, but also Solary, and determined by the motion of the Sun; that is, the space wherein the Sun doth pass 30 degrees of the Ecliptick. By this month _Hippocrates_[SN: De octomestri partu.] computed the time of the Infants gestation in the womb; for 9 times 30, that is, 270 daies, or compleat 9 months, make up forty weeks, the common compute of women. And this is to be understood, when he saith, 2 daies makes the fifteenth, and 3 the tenth part of a mouth. This was the month of the ancient _Hebrews_ before their departure out of _Egypt_: and hereby the compute will fall out right, and the account concur, when in one place it is said, the waters of the flood prevailed an hundred and fifty daies, and in another it is delivered, that they prevailed from the seventeenth day of the second month, unto the seventeenth day of the seventh. As for hebdomadal periods or weeks, although in regard of their Sabbaths, they were observed by the _Hebrews_, yet it is not apparent the ancient _Greeks_ or _Romans_ used any: but had another division of their months into Ides, Nones and Calends. Moreover, Moneths howsoever taken, are not exactly divisible into septenaries or weeks, which fully contain seven daies: whereof four times do make compleatly twenty eight. For, beside the usual or Calendary month, there are but four considerable: the month of Peragration, of Apparition, of Consecution, and the medical or Decretorial month; whereof some come short, others exceed this account. A month of Peragration, is the time of the Moons revolution from any part of the Zodiack, unto the same again; and this containeth but 27 daies, and about 8 hours: which cometh short to compleat the septenary account. The month of Consecution, or as some will term it, of progression, is the space between one conjunction of the Moon with the Sun, unto another: and this containeth 29 daies and an half: for the Moon returning unto the same point wherein it was kindled by the Sun, and not finding it there again (for in the mean time, by its proper motion it hath passed through 2 signs) it followeth after, and attains the Sun in the space of 2 daies and 4 hours more, which added unto the account of Peragration, makes 29 daies and an half: so that this month exceedeth the latitude of Septenaries, and the fourth part comprehendeth more then 7 daies. A month of Apparition, is the space wherein the Moon appeareth (deducting three daies wherein it commonly disappeareth; and being in combustion with the Sun, is presumed of less activity,) and this containeth but 26 daies and 12 hours. The medical month, not much exceedeth this, consisting of 26 daies and 22 hours, and is made up out of all the other months. For if out of 29 and an half, the month of Consecution, we deduct 3 daies of disappearance, there will remain the month of Apparition 26 daies and 12 hours: whereto if we add 27 daies