The Fifteenth British Commonwealth Lecture “Some Recent Progress in Air Survey with Particular Reference to Newly- Developed Territories" was given by W. P. Smith, M.B.E., B.A., F.R.I.C.S. before the Royal Aeronautical Society at the Institution of Mechanical Engineers on 19th November 1959. Mr. Peter G. Masefield, M.A., F.R.Ae.S., Hon.F.I.A.S., President of the Society, presided. Introducing the Lecturer the President said: This lecture was the second of their four premier named annual lectures. The first was the traditional Wilbur Wright Lecture, the second this Commonwealth Lecture, the third was the Louis Bleriot Lecture and the fourth the Lanchester Memorial Lecture. Five years ago, as many of them would recall, His Royal Highness, Prince Philip, the Duke of Edinburgh, honoured them by giving the Commonwealth Lecture on ”Aviation and the Development of Remote Areas.“He thought that they could say that the subject of Mr. Smith's Commonwealth Lecture was in some ways a projection of the Duke of Edinburgh's lecture, under the title "Some Recent Progress in Air Survey with Particular Reference to Newly- Developed Territories.”

Mr. W. P. Smith was a Director and leading light of Fairey Air Surveys Limited. Naturally as befitted a Commonwealth Lecturer, Mr. Smith was a master of his subject—one could almost say that he was “monarch of all he surveys.” He was a Durham man, born in 1920; he was educated at Wellfield School, Durham, and went up to Oxford and took his degree there. During the War, Mr. Smith was in command of Survey Units in the Royal Engineers and after the War he transferred to the Survey Branch of the Control Commission, in Germany. Then, in 1946 he left the Army to join the new Directorate of Colonial Surveys as a Senior Surveyor, and went to West Africa on the Volta River Project. He worked in Africa for a period and then in 1950 he joined Fairey Air Surveys Limited, then known as the Air Survey Company, as many would remember. He was a General Manager then, and was now a Director. So Mr. Smith had spent all his working life dealing with the subject on which he was going to talk about that evening, and in particular, he had been in charge of that vast Kariba Hydro-Electric Survey, on the Zambesi. They could have no one better to talk about Air Survey, and it was said that “life is the art of drawing sufficient conclusions from insufficient premises.” Air Survey, and the sort of things Mr. Smith was going to talk about was, in some ways, a way of filling in some of those insufficiencies.

He had much pleasure in calling on Mr. Smith to deliver the Fifteenth British Commonwealth Lecture.

This paper briefly reviews the progress made with the Imperial College hypersonic gun tunnel since August 1958 when it came into operation. The tunnel and instrumentation are described together with the results of various measurements made both in the barrel and in the working section. More detailed reports will be published later.

With the Co-Operation of 1,600 members of the public a series of aircraft noise assessment tests was made at the 1959 Farnborough Air Show to obtain further information on the way in which the perception of these noises is influenced by subjective effects. This provisional analysis shows that Beranek's empirical method for assessing the perceived noise level is adequate for the comparison of existing types of fixed-wing aircraft. A secondary part of the experiment, dealing with noise simulating the ducted-fan engine, is also described.

Using a Stewartson transformation defined by

it is straightforward to show that in the two cases for which it is possible to find similar solutions to the laminar boundary layer equations with Pr≠1, Le=1, that is stagnation flows Ue∝X and flat plate flows Ue=constant, it is not necessary to assume anything about the specific heats to derive the equations given and solved by Beckwith.

Most University students of fluid mechanics are familiar with the problem of the evaluation of the skin friction drag of a flat plate in the absence of a pressure gradient: transition is specified, usually by the free stream velocity and the transition point, or directly by the transition Reynolds number. The solution is normally obtained numerically: so far as the writer is aware, the processes used have not been written down in closed analytical form, though to do so presents no difficulty.