Was Babbage's Analytical Engine really turing-complete? According to literature, Babbage's Analytical Engine is turing-complete because it supports conditional branching: it can perform different operations depending on the sign of the result last operation using a conditional arm (see http://web.archive.org/web/20100426034840/http://halfbakedmaker.org/2009/12/26/rod-logic-alu-2/).

However, the instruction set as devised by Babbage seems to support only going back or jumping ahead one single punched card. (see http://www.fourmilab.ch/babbage/cards.html, "Combinaritorial Cards")
Surely this is computationally less mighty than supporting a goto-statement for jumping to arbitrary statements?

If any two turing machines can emulate each other, how can the goto-behaviour be emulated using the conditional jumping of just one instruction?
Your question states:


  However, the instruction set as devised by Babbage seems to support only going back or jumping ahead one single punched card.


However, the link you supply as a reference for that says


  The number starting in column 4 indicates how many cards are to be advanced past or backed up past the reader.


This would seem to render your question moot.