@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<http://astrothesaurus.org/uat/433>
  skos:prefLabel "Early astronomical instruments"@en ;
  a skos:Concept ;
  skos:narrower <http://astrothesaurus.org/uat/1841> .

<http://astrothesaurus.org/uat/1841>
  skos:altLabel "PZT"@en, "Photographic zenith tube"@en, "Zenithal tubes"@en ;
  skos:broader <http://astrothesaurus.org/uat/1708>, <http://astrothesaurus.org/uat/433> ;
  skos:prefLabel "Zenith tubes"@en ;
  a skos:Concept .

<http://astrothesaurus.org/uat/1708>
  skos:prefLabel "Transit instruments"@en ;
  a skos:Concept ;
  skos:narrower <http://astrothesaurus.org/uat/1841> .