The paper discusses the influence of wire length on the characteristics of a turbulent flow as measured with a hot-wire anemometer. Most of the mathematical treatment can be directly applied to other problems of length correction, such as may occur, for instance, in problems of astrophysical turbulence, as well as to some problems related to measurements of random processes. The discussion will, however, use the example of a hot-wire anemometer with particular attention to the influence of the length of the wire on the measurement of the intensity of turbulence, correlation coefficients, and scale and microscale of turbulence.

A simple one parametric method, due to A. Walz and based on the momentum and energy equations, for calculating approximately laminar boundary layers is extended to cover axi-symmetric flow as well as plane flow. The necessary computing work is reduced a little.

Another known method which requires still less computing work is also extended for axi-symmetric flow and, with the amendment of a numerical constant, proves adequate for practical purposes.

In a previous paper the author derived, by the Rayleigh-Ritz method, a determinantal equation for obtaining the critical magnitude of any uniform system of edge stress applied to a clamped oblique plate. In the present paper this equation is used to derive values for the buckling stresses of clamped oblique plates subjected to pure shear along and perpendicular to two edges of the plate.

As would be expected, it is found that reversal of the direction of the shear produces a change in the critical value. The lower value occurs when the shear is tending to increase the obliquity of the plate and critical values corresponding to this direction are calculated for 45° oblique plates with side ratios varying between 3/5 and 5/3. The critical values obtained for the reverse direction were obviously very inaccurate, due to the inadequacy of the series which was used to represent the buckling mode. As yet no satisfactory method has been found for overcoming this difficulty.

The problem of a uniformly accelerated slender supersonic aerofoil is solved in this paper by a perturbation method for the cases when the acceleration is small. Full account is taken of the effect of the acceleration on the form of the shock line.

A generalised conical field theory is developed and is applied to delta wings in a non-uniform stream. It is shown that a non-uniform stream may be characterised by the downwash at all points in space. The lift of a delta wing is found when the downwash in the wing plane is given as a power series in the co-ordinates in the wing plane. The basis of the conical field theory is described in some detail but the results only of the calculation of the lift distribution for various down washes are given. The solutions of certain integral equations, required in the calculations, are given in the Appendix.

The three-dimensional boundary layer flow defined by the external irrotational velocity components U = x (ξ), V = αη, where α is a small positive parameter, is investigated with the aid of the boundary layer equations of Howarth. When X(ξ) = ξm a solution exact to the first power in α is found. A Pohlhausen method is then developed for any function x (ξ) and applied to the cases in which x (ξ) = ξm and x (ξ)=i-ξ.