Hi Geoffrey,

It is my understanding that the first CENSUS in the Russian Empire was in 1897.  Before that, there were Revision Lists.  Revision Lists have different rules, standards, and dates than an American Census. 

There are a variety of good articles on JewishGen about the different kinds of documents kept in the Russian Empire.  I found this one in the JewishGen InfoFiles:
_R_What are Russian Revision Lists, 24 Mar 2012.pdf (jewishgen.org)
You can also find discussions by searching this discussion group.

If you are looking for all records about a particular place, you have to keep looking for the town. Records are held in all kinds of unlikely places.

Peggy Freedman
Atlanta, GA USA