Abstract: A cylindrical alkali halide single-crystal-type ingot having an axis generally coinciding with the ?001! crystallographic direction is compressed in a heated dual platen press. To produce an approximately rectangular compressed ingot that is devoid of cracks and fissures at and adjacent the periphery, the surface of the ingot is flatted. For crystals having a face-centered lattice (e.g. NaI), the flat is parallel to the (100) crystallographic plane. For crystals having a body-centered lattice (e.g. CsI), the flat is parallel to the (110) crystallographic plane. The flat is placed on the lower platen of the press to properly orient the crystallographic structure of the ingot with respect to the direction of compression.

Abstract: A holder hermetically seals less than all of the air holes in a zinc-air dry cell and allows air to reach at least of the air holes. This greatly lengthens the lifespan of a zinc-air dry cell.