I have found the source of this charming pen-and-ink drawing, at last.

It was published at:

Corpus Inscriptionum Indicarum.

Vol. I.

Inscriptions of Asoka.

Prepared by Alexander Cunningham

Calcutta:

Office of The Superintendent of Governmment Printing,

1877

Plate XXIX

Best,

Artur Karp

2014-03-09 17:28 GMT+01:00 Artur Karp <karp@uw.edu.pl>:

Sorry for X-posting ---

Dear List,

Does someone know the source of this pen ink drawing?

http://www.safarmer.com/Dhauli.elephant.jpg

Thanks in advance,

Artur Karp