'Burning Glasses' in Ancient India?

[WITZEL at HUSC3.HARVARD.EDU]

This interesting topic of the little studied *ratna* lore has been 
treated at length by Wilhelm Rau in his Academy paper:

"Die Brennlinse im alten Indien" [The burning glass in Old India"],
Akademie der Wissenschaften und der Literatur, Mainz, Abhandlungen der 
Geistes- und sozialwissenschaftlichen Klasse, Jahrgang 1982, Nr. 10,  
Wiesbaden:Steiner 1983, [pp. 26]  

He traces its use in India to the times before our era.

M.W.

-------
Michael Witzel,
Wales Professor of Sanskrit &
Chair, Committee on South Asian Studies,
Department of Sanskrit and Indian Studies
Harvard University
53 Church Street, Cambridge MA 02138 USA
phone 617 - 495 3295, 496 8570, fax 496 8571,
email: witzel at husc3.harvard.edu