Abstract: Lateral packaging for the grouping and holding together of articles superposed in their natural orientation, and presenting a rim which is inserted in a slot of a lateral band with a plurality of sides defined by folding lines.The band is interconnected at its upper part by a panel covering the upper face of the articles, and a series of slots is provided between said panel and said lateral band slots receive the angles or corners of the rims of the articles.

Abstract: Refractometer for measuring the refractive index of a medium (2), using the limiting angle method. A source (4) illuminates a source slit (5) which has as its image with respect to an optical system (S) one of the parallel and regularly spaced slits (5') of a grille (6) fixed perpendicular to the optical axis each of the slits (5') corresponding to an angle of incidence of the optical beam on a prism (3). Turning of a rhombohedron causes the image (5') of the source slit (5) on the grille (6) to be successively on each of the slits (5') of the grille (6). The pupil (L.sub.1), located in the plane of the source, is conjugate with the exit face (8) of the prism (3) and remains stationary when the image (5') of the source slit (5) is moved over the grille (6).

Abstract: Apparatus for guiding aircraft to predetermined parking locations, comprising an optical assembly centered on a reference point, and adapted to provide the pilot in the moving aircraft with two images of a reference point located on the aircraft. When the two images are superimposed, the aircraft has reached the desired location.