Hand bulbs at the end of cords have not been found satisfactory. Various devices have been used, but good systems of fixed lights (bulbs with reflectors and shades), worked well by means of switches, have been perfected.
Reflective Colors. To help diffusion and local effectiveness of both natural and artificial light, inner walls and the whole stack would well be painted some agreeable light tint of enamelled paint. This is a question of taste for the architect, with approval by librarian and committee.
Stack Windows
As stack windows must be high and narrow, they introduce a new and imperative architectural feature on the exterior of the stack fronts. The usual form is a continuous window from foundation to eaves. This may, however, be broken for a foot up from every floor, by a cross band of iron or stone, for effect or for any interior convenience, like continuous hanging of steam pipes, without real diminution of daylight inside, provided that the windows run quite to the ceiling in each deck, to give full top light. If the windows are glazed with wire glass, they will afford some protection from outside fire, and being opaque, would temper the glare of sunlight. Factory ribbed glass is also used, as both tempering and intensifying daylight.
True Windows. To give full effect the piers between windows should be only as thick as the depth of the double book cases, sixteen inches, and directly opposite them. They have only to support themselves and the roof, as the stack floors are independent and self-supporting. Re-enforcement with a steel T-beam will render them stiff enough with sixteen inch width, and even allow flaring from the windows to admit more light.
With this construction, each window can have the full width of the aisle it fronts and be so framed and glazed as not to intercept any light, thus throwing illumination as far as possible down the aisle, with oblique rays from the side of the window to the other side of the aisle, reaching both rows of books to the far end.
This I call a true stack window. In looking over modern plans, you will see that many libraries have them as to position, though the entire available width is not always used.
If you have Clark’s “Care of Books,” see how true the alcove windows were in the Queen’s College, Cambridge, library as long ago as A. D. 1472.