The past year has been one of considerable development and progress in the affairs of the Society, more especially in respect to the large increase in membership, the resumption of the full activities of the Society, the establishment of a Joint Standing Committee with the Society of British Aircraft Constructors, and the transfer of the offices from Adam Street to much more suitable and commodious premises in Albemarle Street.

The accurate testing of aeroplanes is one of the many branches of aeronauticswhich have been greatly developed during the war, and especially during the last year. For some months after the war began a climb to 3,000 to 5,000 feet by aneroid and a run over a speed course was considered quite a sufficient test of a new aeroplane ; now we all realise that for military reasons certainly, and probably for commercial reasons in the future, it is the performance of a machine at far greater heights with which we are mainly concerned.

At the present time there does not appear to be any really adequate theory of the airscrew. The only theory that has been developed recently is the one given by Mr. F. W. Lanchester in a paper to the Institution of Automobile Engineers in April, 1915.

Early in 1915 I had the honour of delivering to one of the largest Engineering Societies in the Midlands, a lecture on "The High Tension Magneto," which is—superficially at least—familiar to all those associated with the Aeroplane and Allied Industries. The present paper is really a continuation of my earlier effort, and, being presented to an Aeronautical Society, I shall naturally make special reference to the high-tension aeroplane type of magneto. The amount of technical literature on this subject available at the present moment is very meagre. It is therefore hoped that this contribution will have the effect of initiating a healthy discussion of ignition problems and stimulating the interest of all members of the engineering industry who are either directly or indirectly interested in the matter.