Abstract: Apparatus for fusing cells, wherein the fusion chamber is provided with a pair of spaced electrodes whose opposite surfaces have such a vertical dimension as to prevent any nonuniform electric field from adversely affecting fusion of cells. The electrodes may comprise a pair of parallel plate electrodes or cocentrically arranged hollow cylindrical electrodes the outer one of which has an inner circumferential surface of a first radius while the inner electrode has an outer circumferential surface of a second radius smaller than the first radius, the difference between the first and second radii being sufficiently small as compared with the whole length of the radii.

Abstract: The invention provides a device for positioning and for holding firmly in a desired position with respect to the vertical an electrode for use in electric spark machining apparatus. The device comprises three horizontal discs in register. The top disc attaches to a spindle and the bottom disc accepts an electrode. The top and middle discs are connected by a settable peripherally located loosely fitting screw; and the middle and bottom discs are connected in similar manner, the screws being positioned 90.degree. apart in the horizontal plane. A pair of rotatable ball bearings, each in an upper and lower socket, acts as fulcrums and spacers, permitting the adjacent discs to be held in register, tilted, and held fixedly in two planes. The tilting effort for each pair of discs is provided by a loosely-fitting spring-loaded adjustable screw positioned diametrically opposite the coupling screw.