At the start of the discussions, the Chairman (Major G. P. Bulman) gave a warning that parts of the subject of transonic wind tunnel testing were still classified and therefore he asked speakers to be careful in what they said. In spite of this, it was possible to discuss a wide range of topics without transgressing security restrictions. Those members of the audience who were familiar with the subject were able to put many questions to the lecturers and to raise several new points, while the large proportion of the audience to whom the subject was relatively new were able to gain a useful insight into the problems involved in the operation and design of transonic tunnels.