Abstract: The invention relates to a method of placing, positioning and fastening railroad sections on railroad rail sections (1) on a number of mutually adjacent and mutually spaced, loose railroad sleepers (2a, 2b), with the aid of a pulling vehicle (7) which functions to pull a rail section (1) from a first railroad wagon (4) into abutment with said sleepers, via a second railroad wagon (5). Rail sections (1) pulled from the wagon by said vehicle (7) are moved linearly at a distance (a) above the sleepers (2a, 2b) with the aid of a number of devices (10, 10a, 10b). This linear movement is adapted so that the trailing end-surface (1′) of the pulled rail section will be positioned adjacent a leading end-surface (1″) of an earlier laid rail section. In this position of the rail section, one or more of said devices (10, 10a, 10b) is/are activated to lower the rail section (1) onto rail-adapted, sleeper-associated fastener elements (81-84).

Abstract: The present invention relates to an image-forming objective which is capable of forming sharp images of objects at at least two different distances from the objective, there being arranged at one focal plane of the objective a corrective element divided into at least two fields in which the refractive power differs between them.