"Sometimes valuable color notes are to be had in crowded buildings where
it is not convenient to sit down and make a large study. For such cases
a small pocket water-color block will be very useful. There is a small
vest-pocket water-color box carrying six colors, which may be set over
the thumb, a water-bottle attached, and with it one can stand unobserved
in a corner and get color notes which otherwise must be passed by. In
studying fresco painting, tempera is very useful. It is mixed up with
water and applied to paper, but may be worked over in the manner of
oils,--a great advantage in making studies.

"The _chambre éclaire_ is invaluable as an aid to drawing, in blocking
out water-colors. It will enable one to make a drawing in an hour which
otherwise would require all day. It is an instrument little known
outside of Paris, but is much in use there among architects. It consists
of a prism mounted on a telescoping leg which may be fastened to the
drawing-board. The eye looks through the prism and sees the building
reflected on the paper; all that remains to do is to trace this outline.
It does not teach one to draw, but it does save time, and produces
better drawings than can be made without it. The best place to buy them
is of Cevalier, on the Seine, near the Pont Netif, Paris. Only those
with the best prisms are of any use: such a one, with two adjustments
only, can be had for sixty-five francs. The table which is necessary for
its use costs fifteen francs additional; that is, a total cost of
sixteen dollars. In buying a table, be sure and get one with sliding
legs which can be taken off the head and packed flat.

"One of the very best ways to study, and one which has very direct
tangible results, is by the aid of printed plates. Take such a book as
Letarouilly's _Edifices de Rome Moderne_. Go to the buildings themselves