at an angle of 45° with the horizontal and immediately over the
machine.
Notes on Basements.
The lucidux, which takes the light from the
pavement prisms, and directs it into the main part of the basement, forms
a natural separation between the vault under the pavement and the main
part of the basement. It has been found very convenient in many instances
to make the lucidux a partition, thus providing in the vault underneath
the pavement lights such rooms as may be required. In the case of
restaurants and cafes, these have been made into small dining rooms, bar
toilets, etc. In the case of stores in basements, the vaults have been used
for shipping rooms.
In designing the iron work which supports the
pavement lights and first floor, is should be carefully noted that the best
results are obtained when the I beams supporting the floor are set with
their bottom flanges flush with basement ceiling. This beam when underneath
interferes with the light materially, and the tables show marked increases
in the quantity of pavement prisms needed for a head beam of any considerable
depth. The bulkhead window is of very little value in illuminating the
body of the basement, and may be dispensed with without any considerable
loss, unless the slope of the bulkhead ceiling is greater than 60° to
the vertical. The small carrying beams which support the iron frames
forming the pavement lights should always be designed so as to run at right
angles to the length of the pavement, as shown in the illustration,
page 75. All pipes in the basement should be so placed
as not to interfere with the light coming from the pavement lights or with
that coming from the lucidux.
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