rs, a bent lever arm
would need to be used, as shown in Fig. 2, but the bend in the
connecting arms brings in another feature that must be provided, as it
allows the wheels to turn either with or against each other, and
leaves two places where the bent arms will come to a dead center. What
is needed here is another element that will take all the twisting
strain on the rod and keep the pitch of both arms alike in every
portion of a revolution. To do this the ball and socket joint will
need to be replaced by a gambrel joint like a ship's compass, and
arranging the bent driving arms as shown in Fig. 3; then the driving
end of the connecting frame will move about in a true circle,
producing as great a tendency to turn the driving wheel in one
position as another. In this arrangement there must be at least six
nicely fitted journals and their bearings, four of which will be
required to take care of the forked connecting rod that joins the
wheels together. Besides all this the bearings must all line up with
the same center that the shafts are centered from or there will be a
"pinch" somewhere in the system. It may seem at first that there must
be more or less end-on movement provided for, and that the bearings
should be spherical; but that it is not the case will be noticed when
all the points are understood to be working from one center similar to
that provided for in bevel gears.--_Boston Journal of Commerce._

[Illustration: FIG. 3.]

* * * * *

THE DECORATIVE TREATMENT OF NATURAL FOLIAGE.[1]

[Footnote 1: Lectures before the Society of Arts, London, 1891.]

By HUGH STANNUS.

_Lecture I._

Sec. 1.--THE ELEMENTS OF DECORATION.

The chief impelling Motives which have caused that treatment of
objects which is now termed _Decorative_, have been:

(a) That necessitated by the Usage, which is FUNCTIONAL;

(b) That resulting from the Instinct to please the eye, which
is AESTHETIC;

(c) That arising from the Desire to record or to teach, which
is the DIDACTIC motive;

The AESTHETIC instinct of the early peoples was gratified by:

(a) The _forms_ of their weapons or tools;

(b) The _patterns_ with which they are decorated;

(c) The _imitation_ of the surrounding animals, e.g. the Deer
scratched on the horn at the British Museum.

Imitation was afterward applied to the vegetable creation; and much of
what is termed Ornament was deri