History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c11.s1.t2: Cire Perdue Casting
History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c11.s1.t2
- Language
- English
Cire Perdue Casting
v1.c11.s1.t2.1
1 2 3 4
v1.c11.s1.t2.2
Fig. 4 Cire Perdue casting method explained: Stage 1. The terracotta core with pins., Stage 2. Wax model of the cat enclosing the terracotta core.; Stage 3. Terracotta covering over the wax model; the arrows indicate inlet and outlet for the molten metal. Stage 4. The molten metal washes out the wax model and replaces it with the metal. The casting is allowed to cool and the clay covering is broken to uncover the bronze figure
v1.c11.s1.t2.3
HARAPPA CULTURE CHALCOLITHIC CULTURE COPPER HOARD CULTURE
v1.c11.s1.t2.4
Fig. 5. Histograms of alloying patterns of protohistoric cultures. Note that only the Harappans use both tin and arsenic alloying. The Chalcolithic cultures use only tin and the Copper Hoard culture only arsenic alloying. This pattern shows that these three technologies were distinctive copper sources used by the Harappans, a large number of ancient copper workings have been radiocarbon dated (Agrawal et al, 1976), but none of the dates so far is older then 3150 B.P. With further work, older working are expected to be found. We have also tried to use comparisons of trace-impurity patterns between ores and artifacts. In both the Khetri (Rajasthan) ores and Harappan artifacts, gold is absent, but a number of other trace elements (silver, iron, arsenic, antimony, lead, bismuth, tin, nickel, zinc, manganese, cobalt, aluminium, copper molybdenum, titanium, magnesium, and vanadium) are present, suggesting the use of the Khetri ores by the Harappans. This method is not foolproof, and it is therefore hoped that results can be reconfirmed by the use of lead isotope ratio comparison between ores and artifacts and also by the techniques used by Chernykh and Tarakhova (personal comm.). Circumstantially, Khetri mines of Rajasthan are likely to have been exploited by the Harappans, because they are found in roughly the same areas.