son of
tint with pen etching, and the "St. Catherine," lately photographed by
Thurston Thompson, from Raphael's drawing in the Louvre, to show the
unity of the soft tinting of the stump with chalk, would be all that is
necessary, and would, I believe, be in many cases more serviceable than
a larger collection, and certainly than a whole gallery of second-rate
prints. Two such examples are peculiarly desirable, because all other
modes of drawing, with pen separately, or chalk separately, or colour
separately, may be seen by the poorest student in any cheap illustrated
book, or in shop windows. But this unity of tinting with line he cannot
generally see but by some especial enquiry, and in some out of the way
places he could not find a single example of it. Supposing that this
should be so in your own case, and that you cannot meet with any example
of this kind, try to make the matter out alone, thus:

Take a small and simple photograph; allow yourself half an hour to
express its subjects with the pen only, using some permanent liquid
colour instead of ink, outlining its buildings or trees firmly, and
laying in the deeper shadows, as you have been accustomed to do in your
bolder pen drawings; then, when this etching is dry, take your sepia or
grey, and tint it over, getting now the finer gradations of the
photograph; and finally, taking out the higher lights with penknife or
blotting-paper. You will soon find what can be done in this way; and by
a series of experiments you may ascertain for yourself how far the pen
may be made serviceable to reinforce shadows, mark characters of
texture, outline unintelligible masses, and so on. The more time you
have, the more delicate you may make the pen drawing, blending it with
the tint; the less you have, the more distinct you must keep the two.
Practice in this way from one photograph, allowing yourself sometimes
only a quarter of an hour for the whole thing, sometimes an hour,
sometimes two or three hours; in each case drawing the whole subject in
full depth of light and shade, but with such degree of finish in the
parts as is possible in the given time. And this exercise, observe, you
will do well to repeat frequently whether you can get prints and
drawings as well as photographs, or not.

And now at last, when you can copy a piece of Liber Studiorum, or its
photographic substitute, faithfully, you have the complete means in your
power of working from nature on all subjects that