A Study of the air routes of the world brings out almost at once the fact that some of the most difficult route are also the most attractive. For instance, the North Atlantic route which couples North America with Europe is certainly one of the most difficult in the world, but also by the fact that it couples two of the most densely populated, as well as the most wealthy groups of people in the world, one of the most attractive.

The electrical power demand in aircraft has shown a very marked increase in recent years consequent on the development of many new airborne electrical devices in the field of armaments, communications and the control of flight. Whereas not many years back the total demand on the largest aircraft could be supplied from a small windmill driven generator of fractional kilowatt output, designs are now in existence requiring 24 kW. generating capacity, while larger loads are projected for future types.

The power distribution problem has therefore been widely modified and the increased importance of the electrical services performed has considerably raised the status of a onetime Cinderella.

The application of strain energy or slope-deflection methods in the analysis of redundant structures leads to a number of simultaneous linear equations with numerical coefficients; the equations may be obtained in such order that each successive equation contains one new unknown, until all the unknowns are so included. This is the only condition essential for the method to be described in the present paper, but the labour is much reduced in slope-deflection and strain energy applications by the fact that most (or all) of the equations contain very few of the unknowns. The method to be given reduces the solving of these equations to a column of successive evaluations, followed by the solution, by algebraic methods, of a small number of simultaneous equations; and a final column of evaluations. In the remaining paragraphs a number of problems are examined to show how the equations may be obtained in suitable sequence for the method to apply. Following an application to the determination of secondary stresses, the operations involved in the moment-distribution method and in this method are compared. A numerical example is worked out in the simple case of §2, and it is shown how any order of mathematical accuracy in the roots may be ensured, provided that sufficient figures have been retained to permit that accuracy.

A meeting of the Royal Aeronautical Society was held in the Lecture Hall of the Institution of Mechanical Engineers, Storey's Gate, St. James Park, Westminster, London, S.W.I, on Thursday, February 15th, 1945, at which a paper entitled “Aeroplane Wheels and Brakes” was presented by Mr.J.Wright, A.F.R.Ae.S. In the Chair, the President, Sir A.H.Roy Fedden.

A meeting of the Society was held in the Lecture Hall of the Institution of Mechanical Engineers, Storey's Gate, St. James's Park, Westminster, London, S.W.I, on Thursday, March 22nd, 1945, at which a paper by Mr. R. H. Bound, F.R.Ae.S., F.S.E., M.I.M.E., A.M.I.A.E., on “Hydraulics for Aircraft,” was read and discussed. In the chair, the President, Sir Roy Fedden.

With the rapid advances made during the war in the power output of piston engines, together with the introduction of straight jet and gas turbine units, the time is very opportune to consider the future scope of the propeller as an efficient means of aircraft propulsion on the types envisaged for the future.

The aircraft designer has taken full advantage of these advances in power unit development by introducing aircraft with ever improving aerodynamic characteristics, thus enabling these increases in power to be utilized efficiently.

The propeller designer has been fully cognisant of these combined developments, and in meeting them has had to make rapid strides in research and development throughout the war period.

In examining the future scope of propellers it is as well to review first the rate at which aircraft and engine development has proceeded over the last six years, as this development would never have been achieved in this space of time had it not been for the intervention of war.

The Thirty-third Wilbur Wright Memorial Lecture was delivered before the Society on Thursday, May 31st, 1945, at 6.30 p.m., in the Lecture Hall of the Institution of Mechanical Engineers, Storey's Gate, London, S.W.I, by permission of the Council of the Institution. The chair was taken by Sir A. H. Roy Fedden, F.R.Ae.S., President of the Society.