00100		Present archaeologists criticize their predecessors,  because
00200	their   excavation   and  record  keeping  methods  lost  information
00300	irretrievably.   However,  present  methods  almost  certainly   lose
00400	information  that  will  be  obtainable  in  the  future, and present
00500	archaeologists are so numerous and so thorough that they  will  leave
00600	few sites for future work.
00700	
00800		Therefore,  it  seems  to me that many sites should be banked
00900	for future work.   In  fact,  perhaps  only  those  sites  should  be
01000	investigated   now   that   will   otherwise   be  destroyed  by  new
01100	construction.
01200	
01300		Here is an example of a technique not now available that  may
01400	get  much more information:  When an object rots, material is leached
01500	out and deposited in lower layers.  Some day it may  be  possible  to
01600	determine  the structure of an object from trace quantities of matter
01700	leached out of it.  When an archaeologist discards  the  dirt  as  he
01800	digs deeper without saving each clod, he destroys this information.