  In the following, bypassing dynamical systems tools, we propose a simple
means of computing the box dimension of the graph of the classical Weierstrass
function defined, for any real number~$x$, by~$ {\cal W}(x)=\displaystyle
\sum_{n=0}^{+\infty} \lambda^n\,\cos \left ( 2\, \pi\,N_b^n\,x \right)
  $, where~$\lambda$ and~$N_b$ are two real numbers such that~\mbox{$0
<\lambda<1$},~\mbox{$ N_b\,\in\,\N$} and~$ \lambda\,N_b > 1 $, using a sequence
a graphs that approximate the studied one.
