an who swims does not increase his motion by kicking
out at an angle, but by drawing the feet together with the legs
straight, thus using the water between them as a double inclined plane,
on which his feet and legs slide and thus increase his motion. The
weight of the steamship is already supported by the water, and all that
is required of the propeller is to push her forward. If set so as to act
in a direct line with the plane of motion, it will use all its force to
push her forward; if set so as to use its force in a perpendicular
direction, it will use all its force to raise her out of the water. If
placed at an angle of 45 deg. with the plane of motion, half the force will
be used in raising the ship out of the water, and only half will be left
to push her forward.

ENOS M. RICKER.

Park Rapids, Minn., Jan. 23, 1886.

* * * * *

SIBLEY COLLEGE LECTURES.

BY THE CORNELL UNIVERSITY NON-RESIDENT LECTURERS IN MECHANICAL
ENGINEERING.

PRINCIPLES AND METHODS OF BALANCING FORCES DEVELOPED IN MOVING BODIES.

BY CHAS. T. PORTER.

INTRODUCTION.

On appearing for the first time before this Association, which, as I am
informed, comprises the faculty and the entire body of students of the
Sibley College of Mechanical Engineering and the Mechanic Arts, a
reminiscence of the founder of this College suggests itself to me, in
the relation of which I beg first to be indulged.

In the years 1847-8-9 I lived in Rochester, N.Y., and formed a slight
acquaintance with Mr. Sibley, whose home was then, as it has ever since
been, in that city. Nearly twelve years afterward, in the summer of
1861, which will be remembered as the first year of our civil war, I met
Mr. Sibley again. We happened to occupy a seat together in a car from
New York to Albany. He recollected me, and we had a conversation which
made a lasting impression on my memory. I said we had a conversation.
That reminds me of a story told by my dear friend, of precious memory,
Alexander L. Holley. One summer Mr. Holley accompanied a party of
artists on an excursion to Mt. Katahdin, which, as you know, rises in
almost solitary grandeur amid the forests and lakes of Maine. He wrote,
in his inimitably happy style, an account of this excursion, which
appeared some time after in _Scribner's Monthly_, elegantly illustrated
with views of the scenery. Among other things, Mr. Holley related how he
and Mr. Church painted the sketch