Imagine winding the hour hand of a clock back from 3 o’clock to noon. Mathematicians have long known how to describe this rotation as a simple multiplication: A number representing the initial ...

As in recent numbers of NATURE my views on analysis have been quoted, and not very correctly, I ask for space to state them more explicitly. I see truth in the quaternion analysis and in the vector ...

JUST as “one shove of the bayonet” was truly said to be more effective than any number of learned discussions on the art of war:— this really practical work, giving genuine quaternion solutions of new ...