Did the ancient Greeks have outside toilets? Up-to-date archaeologists interested in esoteric problems heard last week about a handy way of finding answers to such questionsfor a latrine's humus-rich contents have magnetic properties that vary from the earth around them.
The clever instrument that can tell the difference was the hit of an erudite conference that met at Venice to discuss new methods of archaeology. Called a proton magnetometer, the gadget is based on a principle of nuclear physics discovered only a few years ago. The nuclei of hydrogen atoms (protons) are, in effect, tiny magnets, and they line up like compass...