Johann F. C. Hessel was born in 1796.

Johann F. C. Hessel died in 1872.

z: alternate interior angles

c: consecutive interior angles

f: corresponding angles

x: vertically opposite angles

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern F-C---Z-. That is, eight letter words with 1st letter F and 3rd letter C and 7th letter Z. In alphabetical order, they are:

focalize

Since z = a^2/z on the circle, we see that w as given by (1) is purely

real on the circle C and therefore if* = 0. Thus C is a streamline.

If the point z is outside 0, the point az

/z is inside 0, and vice-versa. Since

all the singularities off(z) are by hypothesis exterior to C, all the singularities

off(a?/z) are interior to C ; in particular f(a

z

/z) has no singularity at infinity,

since f(z) has none at z = 0. Thus w has exactly the same singularities as/(z)

and so all the conditions are satisfied.