==Completely rewritten?== 
 It looks to me like this has been recently and completely rewritten, anonymously and without comments or even a single cited reference, and removing the 1911 Encyclopædia Britannica reference that was previously given. This cannot be entirely good. On the other hand, it doesn't look like a terrible article. I don't have the interest and the patience to evaluated it myself. I suspect that some material from the old version should have been preserved; certainly references are needed. I hope someone will take this on.   |