Magnetism

The book I read to research this post was Magnetism A Very Short Introduction by Stephen J Blundell which is a very good book which I bought from kindle. This book is part of a series where they get an expert to write around 150 pages as an introduction to a subject and they are pretty good. I have reviewed quite a lot of these books. Magnetism can be traced back to the Ancient Greeks who were fortunate to have the rock magnetite literally nearby and it was readily magnetite. Most compounds of magnesium and iron are either readily magnetic or can be made so. It has been shown that muscles require electrical energy to function. The normal way to charge a substance like iron or cobalt is to either pass a magnet over it repeatedly which aligns the atoms so they are charged the same way or wrap wire around it and turn it into an electro magnet. In the 19th century there were something called leyden jars which would store electricity in much the same way as a battery. Thomas Jefferson showed that the charge was stored in the jar itself and not the liquid within which was assumed by many. He would invite friends around before Thanksgiving to watch him electrocute the turkeys on his farm. He also invented the lightning conductor by flying a kite on a piece of string with a strip of metal attached during a thunder storm. There were a lot of vaudeville acts that used electricity and magnetism as part of their act and it's thought he must have watched some of these. I did quite enjoy this book which does contain a lot of information despite its length and it does keep you interested throughout.