Thakkur Pheru (ठक्कुर फेरू) was a Jain polymath scholar from 13-14th c., employed by Alauddin Khilji in his Delhi mint. In Prakrit, he wrote six texts dealing with various scientific and technical subjects. In the following passages, we will cover a short description of each of these. Pheru’s works are important from the standpoint that they also contain a lot of new contemporary information which emerged due to the establishment of Islamic rule in Delhi, and Pheru being a government servant was well acquainted with them.
- धातूत्पत्ति – This text primarily deals with the subject of mining and metallurgy. It has brief methods of extraction and purification of minerals such as copper, bronze, mercury, lead, tin etc. It also deals with perfumery articles viz. Camphor, sandal, saffron etc. The text is very small having only 57 gatha-s and the only point of significant interest here is the contemporary price of many perfumery articles.
- ज्योतिषसार – Composed in 242 gatha-s, it’s a summary of the teachings of preceding acharya-s of astrology namely Varahamihir, Parashar, Garg, Haribhadra etc. Out of the three limbs of astrology, it primarily discusses the determination of suspicious or inauspicious moments.
- वास्तुसार – It’s an important text which has been composed in 205 gatha-s and deals with three primary subjects – residential architecture, iconometry of Jain images and temple architecture. By Pheru’s time, Jain inconometry and temple architecture had matured. The content of the section related to residential architecture is more or less a summary of the extant texts on this subject. The section on Jain iconometry and iconography is quite important for the historical study of Jain images from that period.
- रत्नपरीक्षा – This is a text on gemology composed in 132 stanzas. India has been a major consumer of gemstones since the times of Mahabharata and it was important for the traders to have a good knowledge of this subject. In texts such as Arthashastra, Divyavadan, Agastimal, Brihatsamhita etc., there are good references for examination of gems and it’s also one of the 64 arts which is mentioned in Kamsutra and other sources. Pheru mentions the vast collection of gems in Khilji’s treasury. He gives details related to the various categories of gemstones, their occurrence, merits and demerits and prices. Some of the gems mentioned by him are diamond, ruby, pearl, coral, topaz etc. His original contribution is giving information on gems imported from Greater Persia. He writes about the import of turquoise, spinel and cornelian from these regions. He also gives the details of prices of these gems prevalent in his time.
- गणितसारकौमुदी – As the name signifies, it’s a text on mathematics. It contains standard sections related to mathematics such as arithmetic, geometry, mensuration etc. There is some new information which belongs to Pheru’s own ingenuity. The most important amongst them is giving the formula for conversion of dates from Vikram Samvat to Hijari calendar. He was probably the first to do it. His work on magic squares is also quite interesting. Commercial arithmetic is also dealt with. Considering there were new conventions in architecture also being developed, he gives the formula for calculating the volumes of domes and arches. He gives brief information of crop yields as well. Eg.: Yield of cotton in autumn harvest was 16 man per bigha.
- द्रव्यपरीक्षा – This is his most important work that was directly relevant to his profession. The subject matter is coinage and the examination of metal content in different types of coinages. During that era, kings of each region used to mint coins with varying metal content. Fixing the exchange rate was a major challenge because it requires determination of metal content of the coins for which the exchange rate was being calculated. The first part of the text deals with the different aspects of identification of metal content and exchange rate. The second part is a veritable goldmine for the historians because it has a catalogue of contemporary coins. In total, he writes about 260 types of coins and gives their details such as their name, weight, metal content, exchange rate etc.
References:
1. रत्नपरीक्षादि-सप्त-ग्रंथसंग्रह, edited by Jinvijay Muni, 1961.
2. The Dravyapariksha of Thakkura Pheru by S. Rajeswara Sarma, 2021.