Before passing to the subject of the paper may I ask your indulgence for my limited knowledge of English, which prevents my giving a free discourse, and constrains me to a set lecture. This I view with regret since it makes it difficult to impart to my words the lively and vivid feeling which a more formal picture of the importance and attractiveness of gliding flight may not give.

We are looking back on ten years of development and on an unbroken series of ten gliding competitions held at the Wasserkuppe in the Rhön, since 1920.

The site of the Flying School was selected on a gentle eastward slope about midway between the southern slope of the “ Wasserkuppe ” and the western slope of the “ Weltensegler,” a ridge running at right angles to the former, the slopes of which are most used for training glides. The hangar, 60m. by 12m., was built of timber, with a cantilever roof requiring few supports and with drop doors at each end. The pupils are boarded at the school for convenience and for better supervision and direction of their spare time activities. It was also necessary to provide workshops and offices, and quarters for the mechanics and instructors and for the head of the school. A single building, also 60m. by 12m., adjacent to the hangar contains living quarters below, and a workshop above; a long central passage leads to a hall, on the south side, off which are the quarters of the Director of Research and of the Head of the School, and the kitchen premises; on the north side a woodworking shop equipped with a combined plane and shaping machine, a combined circular saw milling and slotting machine, and a hand saw.

With the present-day normal type of wing the spars are the principal members, and I propose to start by tracing very briefly the evolution of the spars which are used in the Wapiti wings to-day.

The personnel of the Steel Wing Company have been designing and making spars ever since 1912. I shall start from the time when we first began to use what might be described as the box type of spar, which was composed of four strip steel sections.

The first spar that we made of the box type had channel webs with flat flanges, which had only shallow corrugations, and the rivetted joint was flat. This spar was not very efficient in steel, so we deepened the corrugations and curved the rivetted joint, and this gave a better result.

During the early stages of the development of aircraft in the pre-war days it was realised that wireless communication would provide the only satisfactory means of maintaining contact between an aeroplane and the ground. Although the technique of wireless was in its infancy at the time, it must be remembered that the needs of aviation in this respect were correspondingly limited; pilots of early types of aircraft had their time fully occupied in keeping their machines in the air at all, and had no energy to spare for communicating with persons on the ground.