Swallow: a new almanack for the year of our lord God, 1728 [electronic resource] : being the bissextile or leap-year: and from the world's creation 5731. Calculated properly for the famous university and town of Cambridge, where the North-Pole is elevated 52 degree 12 min. above the horizon: and may serve indifferently for any other place of this kingdom. Imprimatur. S.L. Maij 19. 1727