Swan [electronic resource] : a new almanack for the year of our Lord God 1680 : being the bissextile or leap-year, and from the creation of the world at the spring 5683 years compleat : wherein is shewed the principal aspects of the planets, with other coelestial observations, the beginning and ending of Cambridge terms, with other th[i]ngs of note in the university : calculated properly for the famous university and town of Cambridge, where the pole is elevated 52 deg. and 17 min. above the horizon.