<1r>
 Annis 365 $\frac{1}{4}$ d. − 11′. 13″. 92 365 $\frac{1}{4}$ − 11′. 31″. 2 365 $\frac{1}{4}$ − 10′. 56. 64 365 $\frac{1}{4}$ − 10′. 48″ Ann. Greg

10′. 48″ // 10′. 56″. 64 // 11′. {illeg}{illeg} 13′. 92 // 11′. 31″. 2 facit in annis 5000 facit 37 $\frac{1}{2}$ , 38, 39, 40 dies respective.

## Observationes Hipparchi

 Anno Periodi 3 Calippi Ante Christū Alexandriæ Temp. appar Grenovici Temp. med Grenovici Locus ☉ ex calculo si annus 365$\frac{1}{4}$ dies − 11′ 17 162 Sept 27 sub occas. ☉ 27.d 3.h 44′ 20 159 Sept 27 sub ort ☉ 26. 15. 44 21 158 Sept 27 in ips. merid. 26. 21. 44 2|3|2 147 Sept 26 media nocte 26. 9. 44 32|3| 146 Sept 27 mane 26. 15. 44 3{illeg}|2| 146 Mar 24 mane et iterū hora diei 5ta 23. 15. 44 & 23. 20. 44 36 143 Sept. 26 vesp. 26. 3. 44 43 135 Mart 23 circa med. noct 23. 9. 44 49 128 Mart 23 sub occas. ☉ 23. 3. 44 162 Sept 26|7|. 13{illeg}$\frac{1}{4}$ 26. 22. 59 158 Sept 27. 12 $\frac{1}{2}$ 26. 22. 14 146 Sept 27. 10 $\frac{1}{4}$ 26. 20|19|. 59 159 Sept. 27. 1 $\frac{3}{4}$ 26. 11. 29 147 Sept. 27|6|. 23 $\frac{1}{2}$ 26. 9. 14 143 Sept. 26 22 $\frac{3}{4}$ 26 8. 29 17 162. Sept. 27. 00.44 27. 06. 0 − 5. 16 20 159 Sept. 27|6|. 17|8|.11 26. 18. 0 + 0. 11 21 158 Sept. 27. 00.00 27. 00. 0 + 0. 00 32 147 Sept. 26. 15.59 26. 12. 0 + 3. 59 33 146 Sept. 26. 21.48 26. 18. 0 + 3. 48 36 143 Sept. 26. 15.15 26. 06. 0 + 9. 15 32 146 Mar 23. 20. 1 23. 20. 30. (6) + 12. 29 (2. 5 − 0. 29 43 135 Mar 23. 12. 0 23. 12. 0 − 0. 0 49 128 Mar 23. 4.43 23. 06. 0 − 1. 17 50. 3) − 1. 46 (35 $\frac{1}{3}$

− 7.′ 14″ æq. t.

 Diff merid 2h 15′ Diff merid 2h 15′ Temp appar mediocre cor Alexand Temp appar Grenovici Alexand Temp. appar. Grenovici 27. 8. 5 26. 22. 39 26. 20. 24 26. 20. 5 26. 16. 6 26. 13. 51 27. 2. 5 26. 21. 55 26. 19.40 26. 14. 5 26. 13. 54 26. 11. 39 26. 20. 5 26. 19. 43 26. 17. 28 26. 8. 5 26. 13. 10 26. 9. 55 23. 20. 36 23 18. 21 23. 12. 35 23. 10. 20 23. 5. 18 23. 3. 3

And at ye end of every 500 years the larger period of \lunar/ months wch shall or should be then running shall contein only 45 m lunar months & consist of \the/ three lesser periods each of wch shall \of wch that larger period consists shall each of them/ contein only 15 \lunar/ months, the two last months of the \two/ periods {illeg} \co conteining/ 17 months being \then/ omitted.

The advantage of this Calendar above ye Gregorian \in respect of the solar y/ is that in ye Gregorian the Solar year errs a day in 5000 years in this it errs a day & by that error recedes from ye state it had in ye age of Christ, in this it errs a day in 10000 years & by that error approaches the state it had in ye age of Christ so that in 30000 years it will a the equinox will fall on ye 24th of March as it did in ye age of {illeg}|C|hrist & in 110000 years the beginning of Ianuary will fall on ye winter solstice as it ought to do. Also ye recconing by 500, 1000, 1500 &c runs in rounder \& fewer/ numbers then that by 400, 800, 1200, 1600. And tho ye Kalendars differ yet ye stiles \they/ will agree \in stile/ for 700 years to come.

<1v>

The advantage in respect of ye Lunar year is that much greater. For \in/ the Gregorian Kalendar the full Moon on wch Easter depends requires is not to be found wth out ye help of \three or four/ Tables, & when you have that full moon there is no rule in that Kalendar for finding ye other full moons & ye new moons throughout ye year. But in this Kalendar \all/ the new & full Moons are found perpetually without any Tables at all or any other recconing then ye continuall addition of ye 2|3|0 & 29 days wch is so \very/ easy a work that any Novice may perform it. And besides this rule is exacter then ye Gregorian for that errs thre hours & t in 2|3|9 years this errs but 3 hours in five hundred years.

[Editorial Note 1] <3r>

The advantage of this Kalendar above ye Gregorian in respect of ye solar year is that ye solar year in ye Gregorian errs a day in 5000 years & by that error recedes from ye state it had in ye age of Christ, in this it errs a day in 10000 years & by that error approaches the state it had in ye age of Christ so that in 30000 years the equinox will fall on ye 24th of March as it did in ye age of Christ & in 110000 years the beginning of Ianuary will fall on ye winter solstice as it ought to do. Also the recconing by 500, 1000, 1500 &c runs in rounder & fewer numbers then that by 400, 800, 1200, 1600 &c. And tho ye Kalendars differ yet they will agree in stile for 700 years to come.

The advantage in respect of ye Lunar year is much greater. For in ye Gregorian Kalendar ye full Moon on wch Easter depends is not to be found wthout the help of three or four Tables, and when you have that full moon there is no rule in that Kalendar for finding the other full moons & ye new moons throughout ye year. But in this Kalendar all ye new & full moons are found perpetually wthout any Tables or any other recconing then ye continual addition of 30 & 29 days alternately wch is so very easy a work that any Novice may perform it. And besides this rule is much exacter then the Gregorian for that errs three hours in 39 years this errs but 3 hours in 500 years, & may be corrected evey {sic} 500 years to keep it exact.

[Editorial Note 1] Folio 2r is blank. A series of calculations on f. 2v is here omitted from the transcription.