I've been having a look at Thidé's treatment of magnetostatics in the free ebook www.plasma.uu.se/CED/Book/EMFT_Book.pdf
A couple of questions, about embarrassingly simple matters that I've forgotten:
1) In equation (1.11), is it a mistake that the magnetic force between two current-carrying loops depends on on the position vector x? It looks to me as if it's supposed to be an integral over all the "two-body" forces between infinitesmal current elements in the two loops, but this surely shouldn't depend on the location of an arbitrary point on the first loop- or am I misunderstanding the meaning of this equation?
2) He defines the magnetic B-field as the current->0 limit of the magnetic force at a point, in equation (1.15). Is the right way to think about this firstly to think about the force that acts on a current element located at x, and then take the limit of that current going to zero?
Thanks in advance.