Pulse_________ ___________

arteries consequent upon Hit: intermittent in-
jection of Mood into their trunks from the
heart durinir its contraction period. It is per-
ceptible to the touch in all excepting vcr>
minute arteries, and, in exposed positions, is
visible to the eye. The pulse is usually ex-
amined at the radial artery at the wrist.

Pulse, a name common I v given to the ed-
ible seeds of leguminous plants, such as peas
and beans.

Pulsometer, the nann- of a well-known and
widely-used steam-pump, See PUMPS.

Pulszky, Franz Aurel (1814-07), Hun-
garian politician and writer, was born at
Kperies. He was appointed undrr-secrctary of
State for foreign affairs in 1848, but under
suspicion of revolutionary activities, lied to
London, and later accompanied Kossuih to
the United States. Ills works include, Ex-
tracts from the Diary of a Hungarian Travel-
ler in Cirat tin lain (iS.tf); White, Red, and
Jihick (1852), a description of his travels
through the United States.

Pulteney, William, Earl of Bath (1684-
176.}), 1-JHtish statesman, was born in Lon-
don. Tie started the Craftsman (1726), a
journal devoted to the abuse and ridicule of
Walpole.

Pultusk, town, Lomizu government, Po-
land. Hero Charles xn, of Sweden defeated
the Saxons in 1703, and here, too, was fought
a drawn battle between the Russians and the
French (Dec. 26, 1806); p. 13,742.

Puma, Cougar, or Mountain Lion ("Pells
coneolor)) the large American cat, or 'pan-
ther,* formerly to be met with anywhere
from the St. Lawrence River and southern
British Columbia to Patagonia, but now
practically exterminated e. of the Rocky

Puma,

Mountains. When hunted with dogs (the us-
ual method), it tries first to flee, and when
overtaken climbs a tree, where it remains,
snarling at the pack of dogs until the hunter
comes up and despatches it, nevertheless,
vvhtin cornered it fights to the death. Consult
Theodores Roosevelt's Pastimes of an Ameri-
can Hunter; W, H. Hudson's The Naturalist,
in La Plata and Idk Days in Patagonia.

Pumice, or Pumice Stone, a light-colored,
very porous volcanic rock, consisting practic-

3876 ____________Pumps

ally entireh of glassy matter, resembling a
vitreous Iroth. It** peculiar structure* is due
to the sudden expansion of great quantites
of steam imprisoned in a molten lava when it
reaches the surface and is relieved from the
great pressure to which it had been subjected
within a volcano. Tn <ome cases the expan-
sion is so great and rapid that the rock is
Mown into dust, this being the origin of the
great dust clouds which circle round the
earth after the eruption of Krakatoa. Pumice
is used us a polinhing and smoothing material,
also for cleaning surfaces, and in fine powder
is mixed with soaps or used for brightening
metals. The best quality is obtained from the
Lipari Islands. In the United States the chief
deposits are in Nebraska.

Pumpelly, Raphael (iS.^-K^), Ameri-
can geologist, born in Oswego, X. Y, lie or-
ganized the economic geology department of
the U. S. Geological Survey, and was a special
geological agent of the tenth U. S. Census,
1870-81.

Pumpkin, an annual trailing plant sensitive
to frost, and found in cultivation by the In-
dians when America was discovered. As com-
monly grown in the northern United States
the fruits arc yellow, w i t h a hard rind,
gourdlike in form, and more or less hollow.
They are extensively used for making pics
and for stock feeding.

Pumps.—A simple, classification of pumps
would be as follows: (i) Lift pumps; (2)
force pumps; (.0 combined lift and force
pumps. A lift pump is one that gives motion
to a fluid by lifting, without subjecting the
fluid to pressure, A force pump, on the other
hand, uses pressure to induce the flow of
liquid. Any one of the foregoing types may
be single-acting or double-acting, A single-
acting pump discharges only during the
movement of the piston or plunger in one
direction, whereas a double-acting pump dis-
charges during the movement of the plunger
in each direction. Pumps may be either re-
ciprocating or rotary, depending on the kind
of motion given to the moving element; and
according to position 1ht»y may be either
vertical or horizontal Fig, r shows a double-
acting bucket-and-plungcr pump applied to
the raising of water from a shaft of some
depth,

To understand the action of this type of
pump, suppose the plunger and bucket to be
in their lowest positions, or at the bottom of
the stroke, and let the pump rod move up-
ward. The bucket o, as it is pulled upward
with its valves cloned, leaves a space or part-