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In Diagram XX. the plan of a model room is given to accommodate 40 children. The
children occupy two-thirds of the floor space and the lamps for this area may be hung so as to give
efficient lighting in two ways, according as to whether infants or older scholars are to occupy the room.
For infants the perpendicular distance from lamp to desk must be calculated as 5 feet. Three
lamps will be required in the front row and three over the front row in positions marked A.A.A. For a
room with well-grown children we need only reckon 4 feet as the perpendicular distance from lamp to
desk, and with this shortened distance the power of the lamps is improved by one-third, so that two
lamps over the first and two over the third rows of desks in positions marked B.B. would be sufficient.
The illumination of the teachers' portion of the classroom must be taken separately. Here are hung
maps, charts, and the blackboard. Blackboards or slates should be fixed against the wall with the
right hand slightly tilted forward, as shewn in sketch. They should always occupy the right hand half
of the wall behind the teacher. For illumination, when daylight fails, a pendant should be hung to the
left of the teacher's desk in the portion marked X ; this light should be fitted with a chimney and a
metal shell-shaped reflector, opaque to light, to project the light well on to the blackboard or master's
desk as required, and to present a dark back to the children.
Electric Lighting. Handiness, simplicity, and ease of distributing points of light, complete
absence of shadows below the lamp, the possibility of perfect reflection, healthiness in freedom
from consumption of air and production of fumes, and noiselessness, make lighting by the electric
glow lamp the most perfect means now available for school use, the only drawback being its present
greater cost, as already stated, this worked out in 1905 at about 17 times that of gas.

Two sorts of opal shades are in use in the schools; one subtends 110 deg. in the sides, and has a
vertical depth of 3⅛ in. This shade does not cover the lamp, and the incandescent filament is exposed
to the teacher's eyes. The other shade has sides subtending an angle of 80 deg. and with a vertical
depth of 5 in.; this shade completely screens the lamp from the teacher, and is the one to be preferred
for classroom purposes, as the light below is also increased by one-third. These lamps throw an image
of the filaments. If a sheet of white paper be held under the lamp at the distance of a yard, four bright
stars, each with a bright tail outwards, will be seen marking the corners of a square of one foot side.
At the distance of two yards the separation of the points is two feet. The better the reflector over the
lamp, the less noticeable are these lines. Ground glass bulbs obscure the lines completely, but
frosting the glass reduces the illumination by 25 to 30 per cent.
The only suggestion to be made as to bulbs is that these should be as large as possible, and the
filament twisted in as long a loop as possible. Mr. Harman has also examined the "Tantalum" and the
" Nerst" lamps. The former appears very good, but the latter is unsuitable for schoolrooms.
The distribution of the lamps should follow the lines indicated for the gas pendants. Beginning
at the left hand of the children's portion of the classroom, a lamp should be hung over the centre of the
first dual desk and from there across the breadth of the room at distances of not less than 6 ft. and not
more than 9 ft. for 16 c.p. lamps with 90 deg. shades. With gas the fewest possible number of burners
is desirable, for the more burners the worse the atmosphere; but with electricity, the points of light
may with advantage be more generously disposed, and a cross room spacing of 6 ft. might be uniformly
arranged. A second row of lamps should be hung in the same relation over the third row of desks. The
lamps, as usually hung, err in being hung too far back; for instance, over a back row of desks, with the
idea of their illuminating the desks in front, which they, however, fail to do when the children are
present in their seats. The use of a front row of lamps with tilting shades, to light the blackboard
in the teachers' section of the room, or desks in the children's portion, fails to serve both purposes in
practice. It would be better to use a lamp to illuminate the desk and blackboard and completely shaded
from the children's portion of the room. The most common complaint in electrically lighted schools
is want of light owing to low pressure in the supply. Sudden and total failure also occurs occasionally.
In installing electric light, it should be used in classrooms only. Staircases and passages should be
lighted with gas, naked jets with wire frames. In one old school building, where communication was
from classroom to classroom, and where passages had irregular floor surfaces, the evening classes are
much attended by foreigners, and, in the event of failure of light, the difficulties of exit would probably
have even puzzled the schoolkeeper.
In addition to these ordinary means of illumination used in the schools, there are several other
methods used in America, or on the Continent. The inverted gas burners with incandescence, recently
much used in shop lighting, although they throw the light downwards, have drawbacks for school use.
With an inverted Bunsen burner, the combustion is imperfect, and noxious fumes escape to a much greater
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