Having now dealt with the means by which tricycles are made to climb
hills more easily, I wish to leave the subject of bicycles and tricycles
altogether for a few minutes, to say a few words which may specially
interest those who are fond of trying their power in riding up our best
known hills. The difficulty of getting up depends to a large extent on
the surface and on the wind, but chiefly on the steepness. The vague
manner in which one hill is compared with another, and the wild ideas
that many hold who have not made any measurements, induces me to
describe a method which I have found specially applicable for the
measurement of steepness of any hill on which a cyclist may find
himself, and also a scheme for the complete representation of the
steepness and elevation of every part of a hill on a map so as to be
taken in at a glance. The force required to move the thing up a slope is
directly proportional not to the angle, but to the trigonometrical sine
of that angle. To measure this, place the tricycle, or Otto--a
bicycle will not stand square to the road, and therefore cannot be
used--pointing in direction at right angles to the slope of the hill, so
that it will not tend to move. Clip on the top of the wheel a level, and
mark that part of the road which is in the line of sight. Take a string
made up of pieces alternately black and white, each exactly as long as
the wheel is high, and stretch it between the mark and the top of the
wheel. If there are n pieces of string included, the slope is 1 in n,
for by similar triangles the diameter of the wheel is to the length of
the string as the vertical rise is to the distance on the road. This
gives the average steepness of a piece sufficiently long to be worth
testing, because an incline only a few feet in length, of almost any
steepness, can be mounted by the aid of momentum.

There is only one process, with which I am acquainted, which supplies a