\begin{figure}[htb]
\begin{center}
  \begin{picture}(310,140)(0,0)
    \put(20,20){\line(1,0){100}}
    \put(20,20){\line(0,1){10}}
    \put(20,30){\line(1,0){100}}
    \put(120,20){\line(0,1){10}}
    \put(150,20){\vector(1,0){120}}
    \put(150,20){\vector(0,1){100}}
    \put(20,5){$T_0$}
    \put(120,5){$T_1$}
    \put(150,125){$t$}
    \put(275,20){$x$}
    \put(150,5){$0$}
    \put(250,5){$L$}
    \put(250,20){\line(0,1){100}}
    \put(200,5){$T_0$}
    \put(135,80){$T_0$}
    \put(255,80){$T_1$}
  \end{picture}
  \caption{Palica in robni ter za"cetna temperatura.}
  \label{slika1}
\end{center}
\end{figure}