or three arc lamps, with an opal shade or tray underneath, to reflect the light on to the ceiling, from which it will be deflected in a diffused form downwards over the whole room. A few gas lights should be introduced, especially on the staircases, for use if, from any cause, the electric light should fail.
On gas lighting little need be said. The forms of lighting which convey all the products of combustion away from the room into a ventilating shaft are undoubtedly the best. Sun lights, Wenham lights, the Incandescent system, and Sugg's burners, all have their advocates and opponents. It is much a matter of individual choice. But a word may be said as to the position of the lights, as they are generally placed much too high above the readers for the most effective use of the light. A height of 8 feet 6 inches from the floor will be found to give the best results.
The heating and ventilation of libraries is a question upon which much could be written. Taking all things into consideration, heating by hot water on the low-pressure system gives the most satisfactory results. Hot air and steam are used in many of the larger libraries, and are successful when the funds allow a competent engineer to be engaged to superintend the apparatus. The chief defects of heating by these systems are an extreme dryness of the atmosphere, and the charring of particles of dust and dirt by contact with the redhot sides of the heating apparatus. These can be remedied by careful firing, the insertion of trays
