Crystallographic Models - Bravais Lattices

[Czechoslovakia], 20th century—circa 1950, metal and resin.
Rare set of crystallographic models comprising six models of metallic structures with their original labels. Educational models of crystal lattices used in crystallography. In 1848, the French mineralogist Auguste Bravais (1811–1863) demonstrated that there can be only seven types of elementary crystal units and fourteen possible arrangements of points in space: fourteen different types of lattices, since then known as Bravais lattices.
These systems characterize the various geometric shapes that crystal lattices can take: The cubic (or isometric) system, characterized by a cube; the tetragonal system, characterized by a right prism with a square base; the orthorhombic system, which is a rectangular parallelepiped; the monoclinic system, which is an oblique prism with a rhombus base; the triclinic system: a parallelepiped with a rhombus base; the rhombohedral system: a parallelepiped whose faces are all rhombuses; and finally, the hexagonal system, whose basic element is a right prism with a hexagonal base.
The set is presented with a descriptive label typed in Slovak:
"Názov výrobku [Product Name]: Set of 14 crystal lattice models for ZS [Set of 14 crystal lattice models for ZS] | Diamond | Tuha [Graphite] | ňLad [?] | Oxid Uhličitý [Methane] | NaCl [sodium chloride (table salt)] | Methane [Methane] | Ethane [Ethane] | Benzene [Benzene] | monoclinic P | cubic P | orthorhombic P | tetragonal P | hexagonal P | triclinic P"
The geometric forms listed are all present in this set; however, the rhombohedral (trigonal) lattice is missing.