ManishH wrote:
One thing that could explain it is a quid-pro-quo trade of horses southwards and craftsmen northwards. It's hard to imagine chariots with such robust construction as to be usable after long distance transport (unless you implied the sea route ?). Easier to imagine a craftsman exchange.
Not suggesting that chariots were entirely imported, perhaps there existed some kind of trade deficit or different classes of chariots were being made, such as ones for endurance sports vs heavy duty battle versions. The sea route for import of chariot parts (which could be assembled after unloading) is a likely possibility too.
IMO, India had the need to protect intellectual and "patented" developments at that time, the zinc distillation process was one closely guarded secret and I seriously doubt that craftsman exchange would have taken place due to problems with infringements (foreign craftsmen being spies) and issuing security clearances to Indic craftsmen going abroad.
Very interesting comment on brass. Could you please pass me any references to ancient zinc mines ? I know of tin and copper but hadn't heard of zinc mining during antiquity in Greater Indic regions.
What are the brass fabrication constraints ? I thought RV chariot is mostly wood (takshaka, the word for carpenter, is frequently used for chariot maker and is derived from verb root taksha - to carve). Metal is probably needed at the hub ? Use of metal on rim and spokes is a later development.
1.
By the second half of the second millennium b.c., the chariot was being used by the Persian Empire as merely a "shock" device to throw the enemy into confusion, through the use of spinning brass scythes attached to the axle.
2.There is a paper on the Structure of the Shang chariot, dated to the early Chinese Bronze age (~2300 BC). Though the chariot was used for ritual practices, its surfaces were adorned with polished brass.
3.
Dhokra ware of central and eastern India, for which the lost wax process was used to craft bells and other brass items.
Archaeologists have excavated icons and idols proving that for the last 4,000 years, panchaloha (literally meaning an alloy of five metals) has been most widely used for making icons and idols. This five-metal combination of Cu, Au, Ag, Pb, and Zn was considered to be a highly auspicious composition and is still used for icons cast for worship. The important sources of information on making panchaloha are recorded in ancient Sanskrit and regional literature, with artisans from South India perfecting the technology. Other compositions of panchaloha cited include Au, Cu, Ag, Pb, Fe, and Sn as well as the combination of Sn, Cu, Fe, Pb, and brass. However, because of their high cost, gold and silver are no longer used in general-purpose icons. An alloy made by mixing copper, brass, and lead in the ratio 29:2:1 is commonly utilized for general-purpose icons. In some cases, tin is added in an amount equal to the lead content. Lead is added to make the alloy more malleable so that chiseling and engraving of the icon will be easy. The artisans believe that if the icon is made with copper alone, it will not have a lasting shine, whereas adding a little brass to copper results in a lasting shine and a lower melting point. It may be noted that brass is added as a master alloy to introduce zinc.
Reference: N. Gopalakrishnan, Ancient Indian Knowledge in Metals and Alloys Heritage Publications, Series 38 (Thiruvananthapuram, India: Indian Institute of Scientific Heritage, 2001), pp. 20–21.
4.
Though often referred to as 'Bronzes' these statues seldom use the alloy of Copper and Tin that makes up Bronze because Tin was not said to be pure enough for statues of the Gods and Goddesses. Usually, pure Copper or Brass (an alloy of Copper and Zinc) was used for Metal Casting. Later, the mix of the Alloy changed to 20 parts of Copper, to one of Brass and one of white Lead.
Indian "Metallurgists" had perfected the complex process of extracting Zinc from its ores by the Downward Distillation method that required exceptional care in the type of furnance, retorts and a reducing atmosphere as well as temperature management
Agaria the ancient Brahui tribe of India are the inventers of smelting process. They construct the smelters, collect and process the ore, fuel and other raw materials, produce the metal and make axes, sickles, plowshares etc.
They worship Gonda deity Bura Deo , and their ancestral God is Dulha Deo. With equal devotion they worship Agyasura, Ayasura and Lohasura.
Regarding fabrication constraints, it primarily revolved around difficulty of finishing and aesthetics, due to the higher hardness ratios relative to bronze. An alloy phase diagram should be able to point out the advantage that bronze had in this field. For ritualistic purposes, palanquins and chariots had to be adorned with "gold-like" metal with the finished shine of gold, IMO brass would have been an ideal candidate but the craftsmen would have had their fair deal of struggle with innovating finishing process (primarily due to unavailability of suitable abrasives, risk of scratching etc).
You are probably right with the later development of rim and spokes on chariots, however the Persians did have brass weapons circa 2500 BC.
PS: Apologies for delay.