Calendars.- Guldin (Paul) Refutatio elenchi calendarii Gregoriani a Setho Calvisio conscripti, et opera Davidis Origani editi...[Ad refutationem... paralipomena sive annotationes...], woodcut initials, old ink inscription to title, browned, one or tow rust-spots, small paper flaw hole to Vv1 affecting a couple of letters, contemporary marbled calf, gilt, spine gilt, upper joint split, spine ends worn, Mainz, Johann Albin, 1616 § Romain de Saint-Brieuc. Brevis in Gregoriani calendarii reformationem tractatus, first edition, title with woodcut device, woodcut initials, typographic headpieces, engraved full-page illustration, lightly browned, a few ink spots, contemporary calf ruled in blind, spine gilt with stamp of double-headed eagle, rubbed and stained, spine a little worn and chipped at ends, Paris, Denis Thierry, 1648 § Levera (Francesco) De invicta veritate anni, mensis, et diei passionis, et resurrectionis Christi Domini, eiusque nativitatis..., first edition, title with woodcut device, woodcut initial and tail-pieces, lacking final blank, title stained, marginal tear to D2, contemporary vellum using a sheet with English manuscript to lower cover, stained, Rome, Angelo Bernabo, 1668, 4to (3)

⁂ The first two works concern the reform of the Gregorian calendar which took place in 1582 but was not introduced to the Protestant states of northern Europe until 1700 and in Britain in 1752, in great part due to the 2nd Earl of Macclesfield, a noted astronomer. The second item is on calculating the dates of the Passion.