The first point to consider is whether the design should take the form of a monoplane or a biplane. For a reasonably low wing loading and high aspect ratio one immediately finds that the structural weight of the wings alone comes-out rather heavy for a monoplane. If to this be added the necessarily relatively high structure weight of the hull and floats, one is led to the conclusion that to keep the weight down so that the machine may come under the term “ light,” a biplane seems preferable to a monoplane. There is also the point that it is desirable to keep the ailerons well clear of the water. This is easily arranged in the case of a biplane by having the ailerons on the top wing only.

One next considers whether it would be preferable to have a twin-float seaplane or a flying boat design. The flying boat can be moored out in all weathers short of a gale. This is a great advantage from the ordinary user's point of view. The twin-float seaplane does not possess, in one's opinion, this advantage to the same degree.

Not to go too far back in years, and to relate a few facts within the lifetime of most of you present to-night, I may commence by saying that it was in 1909 that Admiral Lord Fisher instructed Admiral Bacon to proceed with the design and construction of a rigid airship, attention having been called to the success attending Count Zeppelin's efforts and to the fact that we could not realise the dangers to which we might be exposed until we possessed airships of our own.

Admiral Bacon got into touch with Messrs. Vickers' experts, and Naval Airship No. 1, nicknamed the “ Mayfly,” was built at Barrow. Messrs. Vickers deserve all credit for their pioneer work on airship design and construction in this country, and it was only very bad luck that prevented their building the bigger ships.

In his opening remarks, Mr. Young stated that the magneto was an electrical machine of very small compass for converting mechanical energy into electrical energy at a very high potential. The electrical energy appears as high tension sparks which occur at regular intervals and in synchronism with the movement of the pistons. Each spark is the result of a very rapid rise of pressure in the secondary winding of the armature of the magneto. To-day magnetos are being produced capable of giving regularly 16,000 sparks per minute or 270 sparks per second.

The paper to be given this evening will describe the methods used and the sequence of operations in erecting a machine which has been delivered new or overhauled from the makers, as distinct from carrying out repair work.

It is proposed to commence with the methods used for checking the correct assembly of components and the rigging of an erected machine. We will assume that a machine has been delivered to the owner in a dismantled condition; that is to say, the wings, tail units, undercarriage and centre section have all been received separately, and it is necessary to entirely re-assemble the machine. It is assumed that the machine is in good condition and that each component has been approved already.

The wind channel and the whirling arm have been devised and perfected over a period of a number of years with a view to providing reliable aerodynamic data for aircraft designers. Of late years the wind channel has been used considerably more than the whirling arm.

In the two pieces of apparatus distinct methods are used. In the whirling arm the model is carried through the air, which is stationary, in a circular path by a long arm. In the wind channel, on the other hand, the model is stationary and a current of air is caused to flow past it.

Various types of wind channel have been evolved, but I intend to describe fully the English wind channel in its present form, as perfected by the National Physical Laboratory and the Royal Aircraft Establishment, Farnborough.