"spurious" leading in latex

Question

the following latex input:

\rule{1cm}{1cm}\\
\rule{1cm}{1cm}

leaves a gap of about .35mm between the boxes. what is the length that defines this gap?

Answer 1

Edit: I was only partly right at first, but GoogleBooks knew. It pointed me at A Beginner's Book of TeX By Raymond Seroul, Silvio Levy, Silvio Vieira Ferreira Levy, which says:

Three variables control this behavior \baselineskip, \lineskip and \lineskiplimit.

The default separation of lines is \baselineskip, but boxes are not allowed to come closer than \lineskiplimit. If they would, the vertical spacing is adjusted until \lineskip space lies between them...