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A FUNDAMENTAL method of determining the distribution of lift across the span of, e.g., a monoplane wing is that of Graphical Successive Approximation, proposed originally in 1923 by A. Fage and B. N. Jurieff independently.

THE fundamental question of the theoretical calculation of the effect of sweep on the distribution of lift across the span of a monoplane wing has, so far as the present writer is aware, been treated only by G. Andreoli and ?. M. Minski, the former paper being known to him unfortunately not in the original but only through a brief mention in the latter. Minski states that Andreoli approached the question by assuming the wing bound vortices curvilinear and passing through the locus of aerodynamic centres of the chords, the investigation being confined to very small deviations from the usual wing vortex system without sweep. However, it is alleged that the pursuit of the problem led finally to rather complicated integral equations insoluble in practice. Hence Minski, adopting the fundamental idea of a curvilinear bound vortex, this time passing through the mean C.P. positions of the chords (one‐third the chord length from the leading edge), proceeded to attack the problem by a somewhat different method, which will first be summarised briefly here since his paper, being in Russian, is presumably not generally known.

THE decision to con ne Imperial Airways and British Airways in a kind of public utility corporation is a curious instance of the adoption by a Government of a proposal made by the Opposition some time before and then rejected. When the Air Navigation Bill was under discussion in the House of Commons, Mr. T. Johnston (Labour) proposed, on May 19th, 1936, that civil air transport should be nationalised, or at any rate that the State should acquire ownership or control to the extent of the subsidy given. This proposal was repeated with more precision by Mr. F. Montague on the third reading of the Bill on July 1st, 1936. Imperial Airways, he urged, should be turned into a “public utility concern, more directly responsible to this House.” “It should belong to the whole community and should be developed for public purposes by the public.” A monopoly fostered by subsidies should not be allowed to create vested interests. The fact that at that time the £1 shares of Imperial Airways were quoted in the market at over 50s. was a pointed reminder that there was some substance in this fear.

THE basic theory of stability has undergone no important modification since the publication of Professor G. H. Bryan's book on Stability in Aviation in 1911. The stability equations derived therein serve to‐day with the difference that axes and symbols have now been standardised and with the additional refinement of a non‐dimensional form of the stability equation introduced by H. Glauert. Due to the vastly increased knowledge of aerodrynamic characteristics, however, the stability derivatives are more readily assessable in any particular design case. This applies more particularly to longitudinal stability calculations which may, and indeed often arc, carried through with no wind tunnel tests available apart from a lift and drag curve for the aerofoil section used. There has also been some extension of the use of stability charts for deriving an approximate knowledge of the behaviour of the aeroplane when it receives a disturbance. These charts are exceedingly useful for obtaining periodic time and damping factor, but the assumptions on which they are based should be clearly realized.

THE greater part of the development of the components of a complicated mechanism, such as an aircraft engine, can with advantage be done apart from the mechanism as a whole. The study of any part can be more complete and improvements in operation effected more readily when it is not necessary to keep the whole working. A carburettor is in many respects a complete unit whose action may be studied with advantage apart from the engine with which it will be used. While the ultimate criterion of the performance of a carburettor is its behaviour on an engine, a great deal can be learned from suitable bench tests in which the engine is replaced by a suction plant; more use could be made of such testing methods than is done at present.

In a recent article, Dr Michael J. Crean (1993) asserts that reinvestment rates of interest must be explicitly taken into account when using internal rate of return (IRR) to compare mutually exclusive investment opportunities. To that end and to measure the risk perceived to be associated with reinvestment, Dr Crean presents two new concepts, namely the combined result of externally averaged numbers (CREAN) and the reinvestment rate risk ratio (R⁴). Presents a response to Dr Crean′s article. Begins by showing that the bulk of Dr Crean′s analysis is a reproduction of research that appeared in the finance literature more than two decades ago. It is also shown that variants of IRR which explicitly take reinvestment opportunities into account are of low economic validity. Such measures offer no benefit to naïve investors, since they are forced to assume that the spot rates of interest determined in the financial markets already incorporate a consensus view of future reinvestment opportunities. Selective investors are also not well served by such measures as the CREAN, as they (just like IRR) cannot be used as an absolute measure of investment attractiveness or to compare mutually exclusive alternatives in the absence of information on the market price of risk. Concludes by taking issue with Dr Crean′s assertion that duration and the R⁴ should both be used to gauge and compare the attractiveness of investments.

May 25, 1966 Building — Safety regulations — “Edge of the roof” — Asbestos roof — Construction — Removal of badly laid sheet — Fall of workman through opening in roof — Whether fall from edge — Applicability of regulation — Sub contractors' failure to comply with statutory requirements — Injury to sub contractor's employee — Liability of contractor — Employee's breach of regulations — Whether co‐extensive with employer's breach — Building (Safety, Health and Welfare) Regulations, 1948 (S.I. 1948 No. 1145), reg. 31(1).

January 20, 1967 Building — Safety regulations — “Edge of the roof” — Asbestos roof — Construction — Adjustment of badly laid sheet —Fall of workman through opening in roof — Whether fall from edge — Applicability of regulation — Subcontractors' failure to comply with statutory requirements — Injury to subcontractors' employee — Liability of contractor — Whether contractor “undertaking” operations — Whether work “performed” by contractor — Building (Safety, Health and Welfare) Regulations, 1948 (S. I. 1948 No. 1145), regs. 4, 31(1), (3).

Offers an analytical tool that measures reinvestment rate risk. Expands the knowledge of the concept of reinvestment vis‐...‐vis the internal rate of return via the external rate of return. Concludes that investors should prefer investments that are less sensitive to reinvestment rate assumption than vice versa.