LETT K IIS ON SC IK NT I I- 1C srilJK< 



derstand your mathemat ic lecturer's name is) and yourself, to 

 ha\e me commended to Mr. Hainbrid^e, \\ith \\hoiii ii 

 you are familiarly acquainted ; and tell him, \\ liereas toward 

 the c-iid of his Vespers 1 lecture, the last act, \\herein he dis- 

 coursed of the reformation of the year and calendar, he very 

 sharply and bitterly inveighed against certain absurd periods, 

 \\herebysome went about to restore the same: I desire to 

 know (which I would further have asked himself, if I could 

 have had any more speech with him, or with Mr. Brig; 

 that time) whether he meant mine or no ? And if mine (be- 

 cause I know none other that hath insisted in the same course), 

 wh.it it is that mislikes him in them ? whether they are not 

 framed according to the right definition of a Period or Annus 

 Magnus ? or whether they be not sufficiently demonstrated, 

 because without a diagramme, to whit, linear, and properly so 

 termed ? w'hich then it will be his part to overthrow by in- 

 stance, propounding some other briefer or better, of another 

 manner and structure, than of Enneadecaeterides and Hen- 

 decaeterides : not Vieta's (consisting of 3400 Julian years), as 

 great a mathematician as he was, and as well skilled in dia- 

 gramms : which (if upon such a sudden, amidst the clutter- 

 ing noise of my labourers about mine ears pulling down my 

 house, and the hammering of my masons to build a new, I 

 rightly conceive) to make a truly defined period, he must 

 correct it by my rules, making it shorter by one whole month 

 of 2i) days than Vieta himself propounded: and so equalling 

 it to eleven halfs of my great period together with my duode- 

 narie period. Or whether he thinks not any period at all 

 profitable or needful for the restoring of the year and calen- 

 dar? But, and if my form of calendar displease him; it may 

 please him to understand, that the calendar is not of the 

 essence, but an accident to the period: as whereunto any 

 form of either lunar or solar calendar may be accommodated ; 

 even the Julian itself: as I have well-nigh two years since 

 declared in the preface of my three Diatribae, as some of my 

 learned and worshipful friends can bear me witness : there 

 being the same reason of the more ancient solar calendar of 

 Dionysius Alexandrinus, and of the Augustan Alexandrinian, 

 with twelve tricenary months, and five or six days appendices ; 

 more commodiously to be placed immediately before either 

 equinox, or the aestine solstice. Hereof I desire an answer 

 with as much convenient speed as you can procure it : and so 

 I commit you to God's gracious protection. 



Yours, 



THOMAS LYDYAT, 



