Abstract: A light source for use in a projection system comprises a pair of lamps each effective to produce a substantially collimated beam. Part of the light emitted by each lamp is directed through the light originating part of the same, or another, lamp. A light combiner is arranged within the path of the light beams from each of the two lamps to provide a composite light beam of a cross section less than the sum of the cross section of the beams produced by each of the lamps.

Abstract: Wall of timber logs is built by fastening log ends to vertical steel studs. Log ends are notched at inner side of wall to present flat notch faces to flanges of studs. Stud flanges are pre-drilled with vertically spaced holes and fasteners are extended through selected holes into log ends. Weather seals are formed between the logs and extruded plastic strip for this purpose is also disclosed.

Abstract: A modular building structure is formed of wall sections of superimposed logs, the logs being slightly flattened on their abutting top and bottom sides and having vertically aligned transverse slots in their ends. The flange of a structural stud, such as rigid vertical channel member, is interengaged with the slots to hold the logs in position, and wooden wedges secure the logs to the stud flange. The logs on the sides of the building generally alternate in their thick end--thin end placement to keep the logs fairly level. Some log sections on the ends of the building have a majority of their thick ends positioned toward the center of the structure to accumulate their heights under the higher portions of the building's gabled roof. The roof includes a series of rafters supported on a series of the structural studs. The rafters are in turn connected to one another by generally parallel purlins running the length of the building.