Abstract: Stops made of a synthetic plastics material in two parts welded together at least at individual locations with a fishing line made of "Nylon". The two parts surround with their inner surfaces a hollow space and form an inner wall with elevations. On welding by means of an ultrasonic field at least edges of the elevations melt together with the fishing line and form a non-detachable connection. By means of radial grooves on the outer side the rigid stop achieves a certain pliability so that a certain transfer from line to stop does not cause any break in the line. Such stops are suitable in ocean fishing for limiting the length of displacement of the swivels.

Abstract: A gaseous fuel is produced, utilizing thermolysis and a water-gas reaction, by heating a piece of carbon through exposure to reflector-focused solar radiation and contacting it with steam. The carbon is at least partially immersed in water within a chamber. A surface portion of the carbon is irradiated by the focused solar radiation through a window in the chamber and through the water and heated to at least 1000.degree. C. A cloud of steam is thus produced in the environment of the heated carbon surface, thereby enabling formation of the gaseous fuel. After being separated from the water, the fuel can be stored indefinitely in a container.