A method of forming a solid inter-layer conductive rod. The cavity may be formed in part by the interaction of a mold a permeate pan and a layer of an adhesive pre-applied to a bundle of the membranes. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided. On the other hand, when stoppage of the operation of an operation lever is detected for a predetermined time period, the idling changeover switch is changed over to its contact c. In one embodiment, the weight plate further includes an interlock for interlocking the weight plate with another weight plate when positioned together. In this case by means of a plurality of lasers disposed in a stationary position one after the other a laser beam is directed at the egg during movement of the egg, and the light transmission of the egg surface is observed by optical observation means.