"perspective glass" meaning in English

{
  "forms": [
    {
      "form": "perspective glasses",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "perspective glass (plural perspective glasses)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [],
      "examples": [
        {
          "ref": "1896, Thomas Nathaniel Orchard, The Astronomy of Milton's 'Paradise Lost', London, New York: Longmans, Green, and Co., page 124",
          "text": "The instrument was at first called Galileo's tube; the double eye-glass; the perspective; the trunk; the cylinder.",
          "type": "quotation"
        },
        {
          "ref": "1906, Herbert Strang, In Clive's Command: A Story of the Fight for India, Illustrated, India: Bobbs-Merrill Company, page 115",
          "text": "He mounted, carrying the only perspective glass the vessel possessed. The captain watched him anxiously as he took a long look.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A kind of early telescope."
      ],
      "id": "en-perspective_glass-en-noun--GHZqXKu",
      "links": [
        [
          "telescope",
          "telescope"
        ]
      ]
    },
    {
      "categories": [
        {
          "_dis": "16 84",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "An instrument for viewing an enlarged image of engraved prints or maps http://www.monticello.org/site/research-and-collections/perspective-glass."
      ],
      "id": "en-perspective_glass-en-noun-Fm~l8Cp0",
      "links": [
        [
          "instrument",
          "instrument"
        ]
      ],
      "raw_glosses": [
        "(historical) An instrument for viewing an enlarged image of engraved prints or maps http://www.monticello.org/site/research-and-collections/perspective-glass."
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "perspective glass"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns"
  ],
  "forms": [
    {
      "form": "perspective glasses",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "perspective glass (plural perspective glasses)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "1896, Thomas Nathaniel Orchard, The Astronomy of Milton's 'Paradise Lost', London, New York: Longmans, Green, and Co., page 124",
          "text": "The instrument was at first called Galileo's tube; the double eye-glass; the perspective; the trunk; the cylinder.",
          "type": "quotation"
        },
        {
          "ref": "1906, Herbert Strang, In Clive's Command: A Story of the Fight for India, Illustrated, India: Bobbs-Merrill Company, page 115",
          "text": "He mounted, carrying the only perspective glass the vessel possessed. The captain watched him anxiously as he took a long look.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A kind of early telescope."
      ],
      "links": [
        [
          "telescope",
          "telescope"
        ]
      ]
    },
    {
      "categories": [
        "English terms with historical senses"
      ],
      "glosses": [
        "An instrument for viewing an enlarged image of engraved prints or maps http://www.monticello.org/site/research-and-collections/perspective-glass."
      ],
      "links": [
        [
          "instrument",
          "instrument"
        ]
      ],
      "raw_glosses": [
        "(historical) An instrument for viewing an enlarged image of engraved prints or maps http://www.monticello.org/site/research-and-collections/perspective-glass."
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "perspective glass"
}