تعيين مقدار جريب در دوره تيموري بر پايه نسخه خطي مختصر در قواعد علم حساب و مساحت

Determination of Acre During the Timurid Period On the Basis of a Short Manuscript Containing Rules in Account Science and Area Measurement

ماليات ارضي يكي از مهم ترين اقسام ماليات و از اصلي ترين منابع درآمد حكومت هاي ايران در سده هاي ميانه بوده است؛ به همين دليل ديوانيان اهتمام ويژه به مساحي اراضي زير كشت داشته اند. باتوجه به اينكه شناخت آحاد پيمايش و اندازه گيري سطوح و مساحت مي تواند شناخت ما را از وضعيت امور ديواني و مملكت داري هر دوره افزايش دهد، پژوهش حاضر بر آن است كه در ابتدا نسخه خطي مختصر در قواعد علم حساب و مساحت را كه رساله اي در آموزش رياضيات و مساحي و مربوط به نيمه قرن نهم ه.ق است، معرفي كند و سپس با تدقيق در متن نسخه به اين پرسش پاسخ دهد كه واحدهاي اندازه گيري سطوح و تعيين مساحت در دوره تيموري چه بوده اند و انتخاب اين واحدها چه نسبتي با نوع ديوان سالاري تيموريان داشته است؟ همچنين براساس اطلاعات نسخه، مقدار «جريب» را برپايه روش اندازه گيري متريك تعيين و ثابت كند كه اين مقدار، مستقل از متغيرهاي ديگر ازجمله نوع كشت و آبياري و بذر است.يافته هاي پژوهش نشان مي دهد كه واحدهاي عمومي براي تعيين مساحت، «جريب شاهي» و «جريب دهقاني» بوده و همچنين در پيمايش سطوح از آحاد «ذراع»، «قبضه» و «اشل» استفاده مي شده كه نسبت مستقيمي با سياست يكسان سازي آحاد و اوزان در عصر تيموريان داشته است؛ همچنين نظريه محققاني مانند لمتون و هينتس كه اين مقدار را وابسته به نوع كشت و آبياري دانسته اند، براي دوره تيموري نادرست است.

Land tax had been one of the most important tax categories and one of the main income sources for Iranian governments during the Middle Ages; therefore, surveying cultivated lands attracted the special attention of the rulers and court agents in that period. Since knowing the units of the survey and measuring the levels and area can increase one's understanding of each period's governmental and state affairs, the present study is initially to introduce a short manuscript containing rules in account science and area measurement firstly, a 15th century treatise on mathematics and geometric education, and then to answer following questions: "What were the units for measuring levels and determining the area during the Timurid period?", and, " What was the relationship between the selection of these measurement units and the Timurid bureaucracy?" an‎d also, according to aforementioned manuscript information and on the basis of the metric measurement method, it has been tried in present study to determine the amount of "acre" and to prove that as a measurement unit it is independent of other variables, including the types of cultivating, irrigation and seed. The findings show that "the king acre" (Djarib-e-shahi) and "the peasant acre" (Djarib-e-dehqani) have been the general units used to survey area, and also other units such as "Dhira", "Qabda" and "Ashl", which were directly related to the Timurids ruling policy of uniformity of length and weight units, were used in land surveying. They also show that the theories of scholars such as Lambton and Hinz that this unit were determined, in Timurid period, upon the types of land cultivation or irrigation are not acceptable.