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162
Annual Report of the London County Council, 1911.
the desks when tilted to the reading position, the illumination was always reduced. This is of
importance because it is not often considered, and yet is the condition under which books are read.
The condition in these rooms Dr. Williams summed by saying that boys near the windows would have
better light than in a well-lighted room at home, whilst those in the remote desks would have lightingmore
comparable to that of a basement or cellar dwelling. Any place where diamond-type cannot
be easily read by a normal eye at half a metre distance has lighting certainly too poor for school
purposes. Whilst the lighting of the separate places affects the individual scholar, the illumination
of the blackboard affects the whole class, and as a rule it is very poor. The contrast between the blackboard
and the chalk requires to be good. For education the object on which the child concentrates
SECOND FLOOR ROOM . F
READING (TILTED) DESKS —
Figure 13.—Measurements of desk lighting in similar room to Fig. 12, but two floors higher.
its attention must have brilliant and clear definition not only in the psychological, but also in the
physical sense. The colours and contrast of chalks have to be considered, especially by artificial light.
Some colours are almost invisible at a short distance, and this is one of several objections to the Dale
system of teaching reading. Measurements of the surface brightness of the best desks and of the
moveable blackboards in a number of class rooms showed the blackboard, on an average, to have only
one-fifth the amount of lighting on the desks. Variations ran between one-third and one-twelfth.
The fixed blackboards were still more poorly lighted, especially in the infants' departments.
Some of the bad rooms, had only about one-quarter of the lighting of well-lighted rooms. Two
rooms compared for a week—one well, the other poorly, lighted—showed a difference of nearly one and
a-half hours daily in the duration of artificial lighting.
Where rooms are poorly lighted they may often be improved by comparatively slight alteration.
Window cleaning will sometimes improve a school room by 40 per cent. in illumination. Borrowed
light, as a rule, contributes very little to illumination for school purposes. A small window in the
back wall is often of much use, particularly in illuminating the blackboard. The light green colour
commonly used in the schools has a comparatively good reflecting power, but above five feet from the
floor white should be used extensively, and woodwork should be white above that height. Dark
dadoes have also to be avoided.
It is, however, when the shadows of the children are considered that regulation of school class
rooms becomes pressingly necessary. All ordinary school class rooms in which the children sit with their
backs to the main source of daylight should now be strictly forbidden. A window surface in the wall
behind the children is excessive if its area exceeds one-fifth the window area in the wall to the child's
left side, although for ventilation and to aid blackboard illumination a window is advisable high up on
the back wall and as remote from the fighting windows as possible.
Glare may be the source of a considerable disturbance. It arises when any source of light throws
a peripheral image on the retina stronger than the illumination of the objects whose images are central,