Stack Direction - Which way does it go?

Hello. I am new to this Q & A thing but it seems very helpful. I was wondering if anyone can help with a general question. I am cutting concrete along the perimeter of my basement to create a French Drain for a seeping foundation. The house is as old as 1850's and the morter joints are giving way to water wanting in. My question is which way does the DWV pipe, which is cast iron, run wants it hits the concrete basement floor? Also, before it makes a turn to the city sewer how far does it go into the ground? Thanks in advance!

I would guess the pipe runs perpendicular to the nearest wall and takes the most direct route toward the city sewer from there, and I would assume it is within reach of a saw blade anywhere inside your walls. If that was my drain line, I would first locate it outside the house before ever renting a saw!

(Same question in different thread: https://terrylove.com/forums/showthread.php?t=11344 )