"needle telegraph" meaning in English

{
  "forms": [
    {
      "form": "needle telegraphs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "needle telegraph (plural needle telegraphs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Electromagnetism",
          "orig": "en:Electromagnetism",
          "parents": [
            "Physics",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Telegraphy",
          "orig": "en:Telegraphy",
          "parents": [
            "Electronics",
            "Telecommunications",
            "Technology",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A telegraph in which the signals are given by the deflections of a magnetic needle to the right or to the left of a certain position."
      ],
      "id": "en-needle_telegraph-en-noun-QsYv3jp1",
      "links": [
        [
          "telegraph",
          "telegraph"
        ],
        [
          "signal",
          "signal"
        ],
        [
          "deflection",
          "deflection"
        ],
        [
          "magnetic",
          "magnetic"
        ],
        [
          "needle",
          "needle"
        ]
      ]
    }
  ],
  "word": "needle telegraph"
}

{
  "forms": [
    {
      "form": "needle telegraphs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "needle telegraph (plural needle telegraphs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Electromagnetism",
        "en:Telegraphy"
      ],
      "glosses": [
        "A telegraph in which the signals are given by the deflections of a magnetic needle to the right or to the left of a certain position."
      ],
      "links": [
        [
          "telegraph",
          "telegraph"
        ],
        [
          "signal",
          "signal"
        ],
        [
          "deflection",
          "deflection"
        ],
        [
          "magnetic",
          "magnetic"
        ],
        [
          "needle",
          "needle"
        ]
      ]
    }
  ],
  "word": "needle telegraph"
}