When Louis Bleriot crossed the Channel for the first time on the 25th July 1909, he certainly did not realise that he was sowing the seeds of a very fruitful co-operation between our two countries in the aeronautical field.

The heaviest inter-city air traffic in Europe is between London and Paris, Bleriot took 37 minutes to cross the Channel but today it takes about three hours to travel from the middle of Paris to the middle of London.

It is a great honour for me to speak to such a distinguished and competent audience. Needless to say, I was pleased to receive the invitation from the Royal Aeronautical Society but was also concerned with the responsibility of treating a subject involving dramatic aspects, which require understanding, and the selection of a certain number of events for presenting a reasonably effective picture of the subject.

I know that it will be impossible for me—for lack of ability and also time—to give a full story of these adventures and ventures and 1 apologise for the omissions. In fact I will only briefly mention some of the facts which have more deeply impressed me or in which I have been directly concerned.

One of the early triumphs of the Lanchester-Prandtl wing theory was that it explained the effects of wind tunnel boundaries and provided explicit and simple formulae to correct wind tunnel measurements for these effects. As every aerodynamicist knows, this theory tells us, with the help of “images”, that the boundaries, in the presence of a lifting wing, produce extraneous velocity components in the flow. At least two generations of experimenters have routinely corrected their angles of attack and their measured drag values for the presence of the vertical component.

The design and analysis of axial turbomachine blade profiles has usually been done assuming the flow to be two-dimensional, that is assuming the blade-to-blade stream surfaces are parallel planes. Similarly, most of the detailed experimental studies of blade profiles have been done in nominally two-dimensional cascades or using wall boundary layer suction to achieve (on average) two-dimensional conditions. In an actual compressor or turbine, however, this condition rarely obtains.

This investigation originated when some difficulties were experienced in establishing good flow conditions in a circular pipe to study the effects of longitudinal cooling on slanted hot-wires.

In the past many investigators have presented results on turbulent flow through pipes and it is now generally assumed that this flow field is known in sufficient detail. For example, Schlichting has given a through description of the mean velocity distribution for turbulent flow through pipes based on the experimental results of Nikuradse. On the other hand Townsend describes the structure of the flow based on the results of Laufer. Although the investigation of Nikuradse and Laufer are classical works there appears to be some uncertainty in whether or not their turbulent flows down pipes were really fully developed.

MIS is more talked about than accomplished. There is also confusion regarding what constitutes MIS and even whether we mean computer based or something broader. Systems claiming to be MIS range from a classical invoicing system which follows well charted directions to $65m development efforts. This paper describes, therefore, past and current thinking on MIS rather than status of individual systems.

It is instructive to follow its history, since although there has been considerable development of theory concerning information during the past few years, efforts at MIS constitute, for better for worse, the main attempts at practical development.

For the past half-century the tank has dominated the land battle by virtue of its armour.

During the last war, the discovery of the shaped high explosive charge (or hollow charge) was the first significant step towards its decline. This type of warhead could penetrate the thickest armour then in use, without the need for its carrier to have any significant velocity. No longer were projectiles of high kinetic energy, and therefore high velocity, required.