{"book":"adl0311","page":38,"text":"جغرافیه طبیعی [ILL]\n۳۵\n\nاثبات کروی بودن زمین\n\nبرای ابطال این خیال که \"زمین یک میدان مسطح است\" ادله ها بسیار اند :-\n(۱) هرگاه یک جهاز طرف ساحل روان باشد- ما اول دود آن را باز تدریجاً سرهای باد بانها و دودکشها و باز خود باد بانها و دودکشها را و باز حصه بالای آن و باز حصهٔ زیرین آن را و باز کل جهاز را می بینیم .\n(۲) اگر شخصی در کنار دریا ایستاده جهازی را که از ساحل دور می شود ملاحظه نماید می بیند که ابتداءً تنه آن مخفی می گردد قدری که کشتی دور تر رفت باد بانها وغیره تدریجاً از نظر پنهان می شود و آخرکار دود نیز مستور و محجوب می گردد معلوم است ـ که تحدب (کجی) زمین مانع رویت شده است اگر زمین مسطح می بود بایستی شخص ناظر تا مسافتی که شعاع بصر آن بتواند تشخیص بدهد همیشه تمام کشتی را به بیند و هر قدر کشتی دور تر شود باید جسامت کوچکتر گردد-","chars":739,"image":"https://storage.googleapis.com/adl-page-images/adl0311/00038.jpg","first_page":1,"last_page":125,"title":"Jughrāfiyā-yi ṭabʻī va Afrīqā جغرافياى طبعى و افريقا","permalink":"https://afghanpress.org/book/adl0311/38","canvas":"https://afghanpress.org/iiif/adl0311/canvas/38","source":"https://afghanistandl.nyu.edu/books/adl0311/","source_pdf":"https://afghanistandl.nyu.edu/pdf/adl0311_download.pdf","rights":{"image":{"statement":"Public domain. NYU states: \"All works presented on this website are, unless otherwise indicated, in the public domain. The images available on this website may be freely reproduced, distributed and transmitted by anyone for any purpose, commercial or non-commercial.\"","uri":"http://rightsstatements.org/vocab/NoC-US/1.0/","holder":"New York University Libraries","source":"https://afghanistandl.nyu.edu/about.html","delivery":"Images are served from a copy mirrored by this project, not from NYU's servers, under the reproduction terms above.","endorsement":"This is an independent project. It is not affiliated with, endorsed by, or reviewed by New York University."},"text":{"statement":"Machine-generated transcription, dedicated to the public domain under CC0 1.0. No warranty of accuracy: see the provenance block on every page.","uri":"https://creativecommons.org/publicdomain/zero/1.0/","holder":"Steps Ventures"}},"provenance":{"text_produced_by":"gemini-3.1-pro-preview","thinking_level":"low","read_completed":"2026-08-09","per_page_confidence":null,"per_page_confidence_note":"Not recorded during the corpus run. No calibrated per-page score exists, and none is estimated here.","human_reviewed":false,"accuracy_context":"Roughly two thirds of characters agree with a modern printed edition of the same text. Much of the disagreement is editorial, not misreading. Treat the transcription as a finding aid and read the page image before quoting.","primary_source":"The page image. The text is an index into it."}}