{"book":"adl0613","page":43,"text":"( 4 )\nobject and No. 1's ivory strip, with his body in Position I (Vide Fig. IV.)\n(b) He has then to maintain the coincidence by gradually bending forwards into Positions II and III (Vide Figs V and VI.)\n(c) In this position whenever he obtains an exact coincidence, he calls \"on.\"\nNOTE I:—When the object gets beyond Position III (Vide Fig VI), he will rapidly advance, so as to get the coincidence again with his body in Position I (Vide Fig. IV) and bend forward as before to Positions II and III (Vide Figs. V and VI)\nNOTE II:—Should No. 1 be reading his drum, No. 2 should seize the opportunity of getting into Position I, so as to lose no time.\nNOTE III:—Now suppose that the object is moving from right to left, No. 2 will assume the forward Position (III) (Vide Fig. VI), first gradually changing to central and Backward Positions (II and I Vide Figs V and IV), and will retire in places where he advanced when taking ranges to an object moving from left to right.\n19.—Observer No. 1's duties.\nNo. 1 will act exactly in the same manner as if taking the range of a stationary object, care being taken to read the range at once when No. 2 calls \"on.\"\nCalculation of Ranges.\n20.—To take a range with an \"ordinary\" 25 yard base or the joint length of the two cords, the figure indicated on the drum D is the actual length of distance in yards.\n21.—To take a range with a \"half base,\" i.e., 12½ yards or the length of one cord, No. 1 must remember to divide figures indicated on the drum by 2.\nNOTE:—Half bases (12½ yards or one cord) give ranges in half-yards; e.g, working with a \"half base\" or one cord, the drum reads 1,500. The range, therefore is 1,500 yards divided by 2 or 1,500/2 = 750 yards.\n22.—To take a range with a \"double base,\" i.e., 50 yards or the joint length of four cords, No. 1 must remember to multiply the figures indicated on the drum D by 2.","chars":1870,"image":"https://storage.googleapis.com/adl-page-images/adl0613/00043.jpg","first_page":1,"last_page":57,"title":"Mīzān al-masāfah مىزان المسافه","permalink":"https://afghanpress.org/book/adl0613/43","canvas":"https://afghanpress.org/iiif/adl0613/canvas/43","source":"https://afghanistandl.nyu.edu/books/adl0613/","source_pdf":"https://afghanistandl.nyu.edu/pdf/adl0613_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."}}