over the sprinkler, and soldered on to the base. Fig. 2 shows the
sprinkler with the cap off, which, of course, leaves the water free to
run from the holes in fine spray in all directions. Fig. 1 shows the
base hollowed out so as to allow the heat to circulate in between the
pipe and the base of the sprinkler, thus allowing the heat to operate on
the _inside_ as well as on the outside of the sprinkler; thus, in case
of fire, it is very quickly heated through sufficiently to melt the
fusible solder. These sprinklers are all tested at 500 lb., consequently
they can never leak, and cannot possibly be opened, except by heat,
by any one. As the entire sprinkler is covered by a heavy brass cap,
soldered on, it cannot by any means be injured, nor can the openings in
the revolving head ever become filled with dust.

[Illustration: PARMELEE'S PATENT AUTOMATIC SPRINKLER. FIG.2--Sprinkler
with cap off.]

It is so simple as to be easily understood by any one. As soon as the
sprinkler becomes heated to 155 degrees, the cap will become unsoldered,
and will then immediately be blown entirely off by the force of the
water in the pipes and sprinkler. These caps cannot remain on after
the fusible metal melts, if there is the least force of water. A man's
breath is sufficient to blow them off.

The arrangement commences with one or more main supply pipes, either fed
from a city water pipe or from a tank, as the situation will admit.
If desired, the tank need only be of sufficient size to feed a few
sprinklers for a short time, and then dependence must be placed upon
a pump for a further supply of water, if necessary. The tank, however
small, will insure the automatic and prompt working of the sprinklers
and alarm, and by the time the tank shall become empty the pumps can