wheels so far as exemption from all trouble is concerned, and others
have never seen any reason for departing from the most used size of 33
in.

One more word about lightness. A wrought iron or cast steel center, 8
or 9 light spokes on a light rim inside a steel tire, makes the
lightest wheel, and one that ought to be in this country, as it is
elsewhere, the cheapest not made of cast iron.

* * * * *




A NEW INTEGRATOR.[1]

[Footnote 1: A paper read before the University College Engineering
Society on January 22.--_Engineering_.]

BY PROFESSOR KARL PEARSON, M.A.


As I fear the title of my paper to our Society to-night contains two
misstatements of fact in its three words, I must commence by
correcting it. In the first place, the instrument to which I propose
to draw your attention to-night is, in the narrow sense of the words,
neither an integrator nor new. The name "integrator" has been
especially applied to a class of instruments which measure off on a
scale attached to them the magnitude of an area, arc, or other
quantity. Such instruments do not, as a rule, represent their results