This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
Poor illumination is frequently caused by ill-designed or poorly constructed brackets or chandeliers. Gas fixtures, almost without exception, are designed solely from an artistic standpoint, without regard to the proper conditions for obtaining the best illumination. Fixtures having too many scrolls or spirals may, in the case of imperfectly purified gas, accumulate a large amount of a tarry deposit which in time hardens and obstructs the passages. Another fault is the use of very small tubing for the fixtures, while a third defect consists in the many leaky stopcocks of the fixtures, caused either by defective workmanship, or by the keys becoming worn and loose. Common forms of brackets are shown in Fig.. 46 and 47, the latter being an extensive bracket. There is an endless variety of chandeliers used, depending upon the kind of building, the finish of the room and the number of lights required. Fig.. 48, 49 and 50 show common forms for dwelling houses, Fig. 50 being used for halls and corridors.