% --- start of displayed preamble in the book ---
vardef magnify(expr pic,p,c,f)=
  save A;picture A;
  A=pic;clip A to p;
  unfill (p shifted -c scaled f shifted c);
  draw A shifted -c scaled f shifted c;
  draw p shifted -c scaled f shifted c;
enddef;

picture pic[];
% ptext=btex ... etex; % image with text not shown
% --- end of displayed preamble in the book ---

verbatimtex
%&latex
\documentclass{article}
\begin{document}
etex
picture ptext;
ptext=btex \parbox{10cm}{\parindent20pt\noindent
  Proposition LX. Theorem XXIII.\hfill\break
  \strut\hskip\parindent
  \emph{If two bodies $S$ and $P$, attracting each
  other with forces reciprocally proportional to the squares of their
  distance, revolve about their common centre of gravity; I say, that
  the principal axis of the ellipsis which either of the bodies, as $P$,
  describes by this motion about the other $S$, will be to the principal
  axis of the ellipsis, which the same body $P$ may describe in
  the same periodical time about the other body $S$ quiescent, as the
  sum of the two bodies $S+P$ to the first of the two mean
  proportionals between that sum and the other body $S$.\hfill\break}
  \strut\hskip\parindent
  For if the ellipses described were equal to each other, their
  periodic times by the last Theorem would be in a subduplicate ratio
  of the body $S$ to the sum of the bodies $S+P$. Let the periodic
  time in the latter ellipsis be diminished in that ratio, and the
  periodic times will become equal; but, by Prop. XV, the principal axis
  of the ellipsis will be diminished in a ratio sesquiplicate to the
  former ratio; that is, in a ratio to which the ratio of $S$ to $S+P$
  is triplicate; and therefore that axis will be to the principal axis
  of the other ellipsis as the first of two mean proportionals between
  $S+P$ and $S$ to $S+P$. And inversely the principal axis of the
  ellipsis described about the movable body will be to the principal
  axis of that described round the immovable as $S+P$ to the first of two
  mean proportionals between $S+P$ and $S$. Q.E.D.\hfill\break
  \strut\hskip\parindent
  (Newton, \emph{The mathematical principles of natural philosophy},
   translated by Andrew Motte, 1848.)} etex;


defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
pic0=ptext scaled 0.4;label(pic0,origin);pic1=thelabel(pic0,origin);
path p[];
p1=fullcircle xscaled 1.2cm yscaled .8cm shifted (0,1cm);
magnify(pic1,p1,center p1,2.5);
p2=unitsquare shifted (-.5,-.5) xscaled 2.5cm yscaled 1cm shifted (-2cm*up);
magnify(pic1,p2,center p2,2);
endfig;
end;