History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c13.s4.43

v1.c13.s4.43

So far as extraction of metals is concerned design of a large variety of pit and shaft furnaces have been already described in the text. In *Rasa Ratna Samuccaya* very precise description of furnaces for various purposes has been given. These furnaces were precisely designed and constructed for specific operation. For example, for making ornaments from silver by Philgree work or for soldering pieces of gold or Silver, jewellers have been using an oil lamp and a tapered brass blow pipe. The desired high temperature at the precise location was developed by blowing air through the blow pipe and diverting the intense flame at the precise spot. It shows that even in the early Vedic period Goldsmiths were aware of the effect of Oxygen blowing on the flame intensity.