Improved Vault and Sidewalk Lights.
We exhibit in Figs. 1 and 2 herewith
printed, an ingenious novelty in the form of a vault light,
with ventilating cover, manufactured by J. C. French & Son,
155 West Broadway, New York. Fig. 1 represents a top view
of this cover, and Fig. 2 a vertical section through the center,
showing it laid on the walk.
The collar which forms the top
section of the vault space, upon which the cover rests, is cut
away at intervals all about its upper edge, and a series of
angle pieces joined to the under side of the cover, and connected
with the collar, holds the cover firmly in place. The edge of
the cover, projecting beyond these angle pieces, does not come
down flush with the sidewalk, but leaves a slight vacant space
there all around its circumference, so that there can be at all
times a free passage of air from the vault to the sidewalk.
There is thus insured constant ventilation, while the construction
of the cover is such as to prevent the access of dirt and water.
Furthermore, the cover is not raised sufficiently about the walk
to become an obstacle to travel. The invention seems well adapted
for its intended service.
In Fig.3 is shown a view of an improved
form of concrete light, which is novel and useful. It is claimed
by the manufacturers to be the only form of concrete light that
can be relied on to be durable in service, owing to difference
in the rate of expansion of glass and other materials, which, if
a rigid joint is employed between them, will be sure sooner or
later to crack the glass by expansion and contraction from
differences in temperature. In this form of tile, an elastic joint
is employed, which is claimed very effectually to guard against
this cause of trouble. There are twenty-nine glasses to the square
foot in this tile, and they are set in taper metallic rings larger
than the glass, the space between being fill with an elastic
cement. They are then placed in the casting and concreted. The
concrete covers both ring and joint, so that they are not visible.
Extensive and prolonged use of tiles provided with lights thus
cemented, have demonstrated their ability to stand the severest
test of changes of temperature--frost and heat-- remarkably well.