History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c15.s1.7

v1.c15.s1.7

Lucas (pp. 434-36) also thought that some process similar to that practised by Mercer may have been in use in ancient times. But at the same time he is rather doubtful, for he is unable to conjecture how it could have been done. He is, therefore, of the opinion that possibly the method employed consisted of two distinct operations (as in the making of modern black pottery in Egypt), the first being the making of a red pot and the second being the subjecting of the rim and the interior of the pot to the action of dense smoke in order to blacken them.