In a recent review of Lamers (Ap. Sp. Sci, 1999, 260, 63) various methods for study stellar winds were discussed, which allow one to investigate the structure of mainly outer parts of stellar winds. Analysis of atmospheric eclipses in WR+O binaries in continuum light provides information on the structure of the inner, photospheric part of the wind, close to a WR core. In this review the results of such analysis for V444 Cyg are presented. It was assumed that both brightness and opacity distributions across the WR star disk are monotonically decreasing concaved/convex functions. Concave part of the function represents the core of the WR star, whereas the convex part describes its extended photosphere. Both functions are assumed to be radially symmetric. This a priori information is independent of the concrete physical model of the WR wind. New spectrophotometric estimate of luminosity ratio was used which allowed us to obtain reliable values of the WR core radius and the orbital inclination.

The results of our investigation show that the motion of the material in the photospheric part of the WR wind (tau_e=0÷0.7) is accelerated. If the acceleration is expressed in terms of Lamers' beta--law the corresponding value of beta ranges from ~1.1 to ~2, i.e. the acceleration varies from moderate to slow.