I. On a magnetic balance, and experimental researches made therewith

In a paper “On the Molecular Rigidity of Tempered Steel,” I advanced the theory that the molecules of soft iron were comparatively free as regards motion amongst themselves, whilst in hard iron or steel they were extremely rigid in their relative positions. I have since widened the field of inquiry by observing the effects of mechanical compression and strains, as well as annealing and tempering, upon the magnetic capacity of sixty varieties of iron and steel, ranging from the softest Swedish iron to the hardest tempered cast steel.