Dr.Disimone,<div><br></div><div>Thank yoy very much for this thought-provoking post.It's curious and intriguing indeed.</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;However,&nbsp; I am curious to know as to whether any speculations can be made&nbsp; regarding the possible time-frame, during&nbsp; which the lead cubes may have existed ?</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Alakendu Das.</div><div><br></div><br>