In 1908 the flights of the Wright Brothers and of Mr. de la Grange turned my attention to aviation. A graduate from engineering and naval constructors' schools and a Lieutenant in the R.N.C.C., I first devoted myself to building an aerodynamical whirling arm (Photo I) which enabled me to carry out some research on aerofoils and airscrew models. As in the Froude's tank, forces, spaces, times and revolutions were registered on continuous diagrams.

Then, in 1910, I started the construction of my first aeroplane, which never went in the air, although it had been provided with an automatic stability device.

From the beginning I understood the importance of being a pilot myself, before taking any risks, so I obtained my licence in 1911, on a land Farman. At that time licences were granted in a very few hours. I remember I had been only twelve times in the air and had had two hours’ flying training altogether.

Among the various applications of meteorology to the practical requirements of everyday life, the observation of fog, as a meteorological element, has. been associated primarily, in the past, with locomotion on land and with navigation on the sea. The first scale of fog intensity used by meteorological observers in this country was, in fact, based on the effect of different degrees of atmospheric obscurity on navigation. The scale was drawn up in 1903 as the result of an investigation into the conditions of formation of London fogs, and subsequently modified by the Meteorological Office, in conjunction with the Admiralty and Trinity House (see Table I.). It included five specifications of fog intensity ranging from a clear atmosphere free from fog or mist, represented by “ of,” to a thick fog, denoted by “ sf.”

Within the last twelve years, while the importance of fog as an obstruction to road and rail transport and to shipping has in no way diminished, the reporting and forecasting of fog has assumed a new significance in relation to air navigation.

In this paper a theory of wrinkling in Sandwich Construction is presented in two parts. In the first part, the thickness of the core is regarded as finite. The wrinkling stress is given by a simple square root formula consisting of the Young's moduli of the materials and the ratio of the thickness of the face and core. In the second part of the theory the same procedure is followed, with the main difference that shearing stresses in the core are also considered, and the analysis is extended to the case where the face is supported by a sufficiently thick or a semi-infinite medium. The result for the wrinkling stress is a cubic root formula which consists of the moduli of the materials but indirectly depends upon the geometry of the structure; this formula is valid only if the ratio of the thickness of the core and the face is greater than or at least equal to the ratio of the width of the marginal zone of distortions in the core, and the thickness of the face. The width of the zone is also useful as the criterion which discriminates between the two cases of buckling as envisaged in this paper. The theory is compared with the previous works, and also with the test results already available. The selection of the experimental data comprises steel, aluminium alloy and Papreg (laminated paper plastic) as the face; and onazote, cellular cellulose acetate, granulated cork, sponge rubber and expanded formvar as the core materials over a wide range of core-face thickness ratio. The agreement between the theory and the tests is satisfactory.

1. (1) Survey of the present methods of carrying out air transport service when visibility is bad.

2. (2) What is essentially required of technical aids for landing under bad weather conditions.

3. (3) Short survey of current German methods for solving the problem of landing in fog.

The necessity for being able to carry out air transport unhindered by weather conditions is inseparably associated with the idea of commercial air service. This great problem of “ flight in any weather ” has confronted us since the inception of regular services between places having corresponding traffic needs, that is to say, since the very birth of air transport.

For the problem of bombing from a distance we may use either ordinary wingbombs or wing-bombs acting by propulsion (e.g., rocket propulsion). The uses of such bombs have been thoroughly discussed by Rougeron in his well-known book “L’Aviation de Bombardement.” (I).