Hello all, I have recently taken up the study of electromagnetism because I found that I lacked severely in this area. This became apparent when I attempted to build a real motor from scratch. Sure I've built motors before, just the old high school coil suspended on two paper clips hooked to a battery etc. This time, I tried to build a real motor which could do real work. So I figure I know the basic function, as far as how it is supposed to work, attraction and repulsion. When it came to actually making it work... nothing. I got enough torque to set the poles of the armature parallel to the field poles, then no more. I did eventually, by trial and error, get it to function. And it now powers a small scroll saw (which I also built), but mostly for novelty purposes. With these failures I figure I must not know what I think I know and I start studying some old books (and I mean old, Hawkins Electrical Guide, 1914). Now these books really have alot of info. My question, right now is this: What is the difference between the B and H fields? Because their ratio is dimensionless, doesn't that mean they have the same units, so why are they described differently in my texts? Thanks.