Sentence:  Next the cold Bears, (the Cause t' himself best known) / Shines forth a kneeling <WSD>Constellation</WSD>. / Behind whose Back Arctophylax appears, / The same Boötes call'd, because yoak'd Steers / He seeming drives; who through the rapid Skies / (Bearing Arcturus in his Bosome) hies. 
Meaning of the word marked with <WSD> tags:  Any of the 88 regions of the sky officially recognized by the IAU, including all stars and celestial bodies in the region. (1920s)