The most widely spread method of determination of star declinations is Bessel's method. Alhough it gives good agreement between star declinations obtained from observations of stars in upper and lower culminations, it leads to great systematic errors if the system of the instrument has an error of the type such as flexure or errors of divided circle. Besides, in the determination of correction of latitude (Δφ) and refraction (Δμ) considerable correlation between them exists.