\begin{figure}[h]
\begin{center}
\footnotesize
\begin{picture}(300,60)
\put(30,20){\circle{40}}
\thicklines
\qbezier(36,40)(45,38)(50,26)
\put(120,20){\vector(1,0){50}}
\thinlines
\put(60,35){turn of length $f$}
\put(60,35){\vector(-2,-1){10}}
\put(20,45){\line(1,-2){5}}
\put(20,45){\line(1,-2){5}}
\put(28,45){$d$}
\put(40,33){\line(1,2){5}}
\put(240,20){\circle{40}}
\put(230,45){\line(1,-2){5}}
\put(255,25){\line(1,0){10}}
\put(248,41){$d'$}
\end{picture}
\end{center}
\caption{\footnotesize Effect of turns of length $f$ on the distance from $d$ to
$d'$}
\label{circles}
\end{figure}