+% Default leading.
+\newdimen\textleading \textleading = 13.2pt
+
+% Set the baselineskip to #1, and the lineskip and strut size
+% correspondingly. There is no deep meaning behind these magic numbers
+% used as factors; they just match (closely enough) what Knuth defined.
+%
+\def\lineskipfactor{.08333}
+\def\strutheightpercent{.70833}
+\def\strutdepthpercent {.29167}
+%
+\def\setleading#1{%
+ \normalbaselineskip = #1\relax
+ \normallineskip = \lineskipfactor\normalbaselineskip
+ \normalbaselines
+ \setbox\strutbox =\hbox{%
+ \vrule width0pt height\strutheightpercent\baselineskip
+ depth \strutdepthpercent \baselineskip
+ }%
+}
+