Increase processes for Apache 1.3 (is 25

I am running a webserver on Linux with Apache 1.3

At the moment apache is configured for 250 proc. I would like to at least double this, I edited the httpd.conf, restarted apache, but comes up with some error that the 250 limit is hardcoded or something like that.

How can I increase this (the easy & save way) ?