EQUATORIAL SUNDIAL Russian patent published in 2003 - IPC

FIELD: instruments determining time by the Sun. SUBSTANCE: equatorial sundial has base with column which upper part carries winter time gnomon mounted for angular movement and position fixing in vertical plane. Summer time gnomon and circle of hour angles made of transparent material are anchored on upper end of winter time gnomon. Base has sight and circle carries reading scale of apparent time and displacement diagram of reading point of local time relative to center of shadow that comes in the form of graph of time equation marked on image of shadows cast by gnomon. EFFECT: capability to read time in winter season, increased convenience of sundial handling and accuracy of reading of local solar time. 5 cl, 5 dwg