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PROGRESS in most branches of engineering has been dependent upon model tests, and in no branch has the testing of models been of greater importance than in that of aeronautics. The earliest flights were made on models; and after the first successful flight of the full‐sized aeroplane, the development of aircraft to their present state of efficiency has been bound up, at every step, with the information obtained from model tests.

The forces on ellipsoidal bodies placed obliquely in a converging or a diverging stream can be found direct by calculation of the pressures on the surfaces. It seemed worth while to do this in illustration of the general question, as a rather plausible line of argument had led to erroneous values of the transverse force. The results are found to agree with those of the indirect, but more general, investigation by Professor G. I. Taylor in R. & M. 1166.

It is usual when carrying out tank tests on seaplane models to include measurements of the change in attitude when pitching moments of different amounts are applied. The measurements are generally made over a range of speeds in the neighbourhood of three‐quarters of the take‐off speed, in the neighbourhood of one‐third of the take‐off speed, and also with the hull or floats at rest. Curves of attitude against speed, with different applied moments, are shown in Fig. 11, for a twin‐float seaplane, and may be regarded as typical.

“WHAT is its top speed?” This is the question which is perhaps most frequently asked about any new aeroplane, and it is certainly a question which is usually incorrectly answered. By this is not meant the natural tendency of manufacturers to be optimistic as to the paces of their latest progeny, but merely that the top speed of an aeroplane cannot be stated with accuracy until a number of careful and methodical measurements have been made. In this article a short account will be given of the errors inherent in the ordinary methods for indicating speeds, and descriptions of some of the methods evolved to measure speed—not only top speed but speed generally—to a high degree of accuracy.

French Republican Model and ‘laïcité, the French version of secularism’, are supposed to protect the citizens, at work or elsewhere, against any form of discrimination and France has a long history of immigration. Ethnical and racial discriminations at work are nevertheless observable towards visible minorities today. People from North African ascendance as well as those from French overseas territories ¹ ’ origins are heavily penalized in the job market. Neither direct and indirect laws nor the ‘voluntary initiatives’ introduced by companies seem able to solve this problem at a time when massive unemployment and terrorist Islamic attacks on the French soil are creating a situation of crisis.

Under this heading are published regularly abstract of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the U.S. National Advisory Committee for Aeronautics, and publications of other similar research bodies as issued.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the U.S. National Advisory Committee for Aeronautics, and publications of other similar research bodies as issued

FOR the first time Great Britain holds the three principal World's air records; for we do not think anyone will cavil at that description of the three “absolute” records of speed, altitude and distance in a straight line. Though we are not directly concerned with them, it may not be out of place to mention also that a British boat holds the World's water speed record and a British motor‐car the World's land speed record, which Sir Malcolm Campbell the other day put a little nearer to the 300 m.p.h. which is the motorist's ideal of the moment. It is not wholly irrelevant to mention these records in other elements since they were both made with Rolls‐Royce engines adapted from those which hold the air speed record.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Notes of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued.

The issue of duplicate publications has received a lot of attention in the medical literature, but much less in the information science community. This paper aims to analyze the prevalence and scientific impact of duplicate publications across all fields of research between 1980 and 2007.

The approach is a bibliometric analysis of duplicate papers based on their metadata. Duplicate papers are defined as papers published in two different journals having: the exact same title; the same first author; and the same number of cited references.

In all fields combined, the prevalence of duplicates is one out of 2,000 papers, but is higher in the natural and medical sciences than in the social sciences and humanities. A very high proportion (>85 percent) of these papers are published the same year or one year apart, which suggest that most duplicate papers were submitted simultaneously. Furthermore, duplicate papers are generally published in journals with impact factors below the average of their field and obtain lower citations.

The paper provides clear evidence that the prevalence of duplicate papers is low and, more importantly, that the scientific impact of such papers is below average.