In this paper the two-dimensional boundary-layer problem of the steady laminar flow of a perfect gas along a thin flat insulated plate has been solved for a wide range of gas velocities and properties. It is found that compressibility and Prandtl number do not introduce any new phenomena, but do alter the drag on the plate, the equilibrium temperature of the plate, and the velocity and temperature distribution through the boundary layer. The drag coefficient for the plate is given by Equation [24] together with Fig. 2. The temperature of the plate is given by Equation [27 a or b], and approximately by Equation [26] or by Figs. 3 or 4. Typical velocity and temperature distributions are given in Figs. 5 to 10, inclusive.