Another useful set of **graphs** comprises those which give the relation between the expressions of a length, volume, &c., on different systems of measurement.

39 The plane figures with which we are concerned come mainly under the description of **graphs** of continuous variation.

1, 2, 3, 4 (plate) show enlargements from photo- General **graphs** by Hansky at Pulkowa (June 25, 1905); Appearance they are separated by intervals from 25 to 80 of photo- seconds, and he has succeeded in showing identity sphere.

(C) Mensuration of **Graphs** Generally.

The second class of cases comprises equations involving two unknowns; here we have to deal with two **graphs**, and the solution of the equation is the determination of their common ordinates.

In particular, the equality or inequality of values of two functions is more readily grasped by comparison of the lengths of the ordinates of the **graphs** than by inspection of the relative positions of their bounding lines.

[[Mensuration Of **Graphs** 38.]] (A) Preliminary.

To illustrate the importance of the mensuration of **graphs**, suppose that we require the average value of u with regard to x.

(B) Mensuration of **Graphs** of Algebraical Functions.

On calculation of moments of **graphs**, see W.

10 But the **graphs** which should contain, besides the normal sitter, representations of deceased friends.

In his theory of **graphs**, or geometrical representations of algebraic functions, there are valuable suggestions which have been worked out by others.