Time-integrated photographs are presented of collimated plasmoid motion parallel to magnetic fields, into and around magnetic flux diverters, into and out of magnetic mirrors, and along curved fields. Field strengths up to 3 weber/m2 were employed. The material projected along the field lines was substantially copper plasma, created by short vacuum spark bursts (plasmoids), and injected into a vacuum chamber. Flux diverters and nonuniform solenoids expanded or compressed the plasmoid, which followed the field lines. In the case of curved fields, at least parts of the plasmoid appeared to be guided by the field lines, the guidance improving with decrease in plasmoid density. In general the behavior was more complicated than with straight geometries because of the presence of internal polarization fields. Photomultiplier studies were employed with some geometries to estimate center of mass and expansion velocities which, in later experiments, reached 5.5 and 1.9 cm/μsec. The latter figure gives an upper bound to ion temperature of 120 ev for copper. This ion energy is considerably higher than those normally encountered in spark channels and is a substantial fraction (0. 12) of the axial energy. A mechanism is described for achieving such a thermal energy through the interaction of a strong shock wave with the initial discharge channel, thermalizing a large fraction of the axial energy. The upper bound for ion Larmor radius was that of the plasmoid. In order to extend the well-known treatment of the mirror reflection phenomenon to such a dynamical plasma, a theoretical total reflection coefficient is derived for a plasmoid entering a magnetic mirror. The experimental equipment is described, and a machine-computational method is outlined for mapping the flux distribution and density in a wide variety of solenoid geometries and combinations.