The paper describes a numerical solution of nonstationary Navier-Stokes equations with two space variables and periodic boundary conditions using vorticity-stream function formulation and finite difference methods. There are examples indicating that sometimes coarse grids yield rather unsatisfactory flow models, especially at large Reynolds number Re (probably, it is a misprint when the authors write \(Re=1/10^4\) on page 153). The examples also show that more accurate approximations might significantly decrease the number of grid points for more realistic flow description. For example, the fifth-order upwind differencing is used for convective terms. Also, the authors apply a fifth-order time integrator. The grids in space are like \(513\times 513\).