822 / 1042
808
H Y DIlO S T A T 1 'C S.
Ifg
eH
almo~
to the
he'~ht
B,
ir the f¡,phon were emp·
t,tdof air, yet the wcight lI'ouldnot be fuRicionl to force
the water over the bend; and therefore, it could never
be brought into the leg B....C.
1'. 111011//1
(Up.
Ln a hole be made quite throllgh the botlomof the
cup A (fig.
11 .)
and Ihe longer legof Ihe bended fyphoo
BeED
he cemenled ¡nto the hole, fo that the cnd
D
of
the {horter leg
DE
mayalmol! touch Ihe
bOlt~m
of the
cup wilhin. Then, if water be poured into thi, cup, ir
will rife in the {horter leg by its upward prdl'ure, exuud·
ing the air all Ihe way before it through the longer leg:
and when the cup is fiJled above Ihe bend of the fyphon
at F, the pretrure of Ihe water in the cup \ViII force it
over the bend of the fyphon : and it will defcend io the
gín to run: and then to amufe othen,
he may calI
OUt
¡lo,'.
or
ru~,
Iccordingly.
Upon this plinciple, we may enfil y Iceount for
inltr.
"Jil/i"l
or
m iproclllilll foringl.
Let AA (fig.
2)
be
pUl of a hill, wilhin IVllich there is a cavity BB; and
fromIhis ,"vilyaveio orchanoel ronoi"g io the direélion
BCDE.
The raio tbat falls
~pon
the fide of the hill
\ViII fink and lll aio through Ihe fm, 1I pore! and cranniCl
G,
a, a, a
j
and fill the cavi[y Hwith water. When
the waler rifes to the leve!
HHC,
tbe ocio
BeDE
will
be filled to
e,
and the water will run through
CDP
as
through a fyphon; which runniog will continue umil the
cavi[y be emptied, aod theo i[ will nop uDtil Ihe cavity
be filkd agaiD.
ThuDmllJM pump.
longer leg
CBO,
aod run throllgh the bOllOm, unti! tbe TH S
cO'lIm~n¡ucUnl
p.mp,wilh which we draw
In-
cup be emptied.
ter out of weJls. is an engine bOlh poeumalic aod hy-
This is
g~neraJl y
called
Tallla'ul'l cup,
and the legs draulie.
lt
cooliOs of a pipe open
at
botb eDds, io whia
of the fyphon in it are . Imol! clofe together
j
and a little
is
a movcable pifion. bu, kel, or fu cker, as big as the
hoJlow f!atu e, or figure of aman, is fometimes pUl ovcr bore of the pipe io thu part wberein it works : and il
the fyphon to conccal it; the bcnd
E
beiog with Ihe neck Jeathered rouod, (o as to 6t rhe bore eltaélly ; aod
of the figure as high as the chino So that poor thirOy maybe moved U? anddown, withoot fufferiog aoy air
tt
Tanlo/ul
ll ands up to the chin in water, imagining
n
come between it and Ihe pipe
oc
purr.p.barrcl.
will rife' a little higher, and ht may dlink; but inlleadof We {hal! explaio theconllruélionboth ofthis and the
that, when the water comes up tO his chio, it immediate- foreing pump by piélures of glafs models, in wnich
Iy begins to rlefcend
j
and fo, as he canno! lloo,p 10 both ('.e atlioo of Ihe pillon; and motioo of the valvea
followit, he is Icft as much paiocd with rhirll as cver. are feen.
Hold the modcl
DCBL
(lig.
3.)
upright in the vetrel
Th,
fo unloín al wnma/lll.
THE device c.1l1ed
Ih_¡,unlain al
command
aets I!pOO
ule fame principie with the fyphon intbe cupo Let two
velfcls Aand B (PIate
e.
fig. t.) be joined togetber by
the pipe
e
which opeos in[o, hem both. Let A be open
ar top, Bclofe both at topand bonom(faveooly a fmall
hole at
b
tO let Ihe air'ge[ out of Ihe vetrel B) and A be
of fuch a fize as to hold abou[ fi x times as much water
asB. Let a fyphon
DEF
be foldered tO the vetrel B, fo
that the part
DE,
may be wilhin the ve!TeI, and F with·
out it
j
Ihe end
D
almoll toltching the bottom of the vef·
{el, and the end F belowthe leve! of
D:
[he vetrd B
haoging at A by the pipe
e
(foldmd into both) and the
'\Vholefupported by th, pillars G and Hupon the lland
I.
The bore of the pipe mull be
coo~derably
!tfs thao Ihe
bore of Ihe fyphon.
The whole bcing thus confiruélcd, let rhe vetrel A be
lilled wilh water, which will run through the pipe
e,
ftnd
fiIJ
the vc!Td B. \Vhen B is fi lled above Ihe top
of the fyphon a[
E.
the I\'ater will run through the
fyphon, and be difcharged at F. Rut fince the bore
of the fyphon is larger than Ihe bore or the pire, the fy–
phonwill run faaer thanthepipe, and will foon eOlply the
vetrel B ; uponwhich the wata will ecafe froOl runoing
Ihrough the fyphon at F, until Ihe pipe
e
le·fi Jls the
vetrcl B, and [hen it will begin
10
run as before. And
Ihus the fyphon will conlinue torun and
llop
alternarel)',
until all the water in the vetrcl AhaHunthrJugh the
p;p~
C.-So that after a fcw trials, one OI'y
ear.lycucfs a·
bout what time tue fyphon willllop, aud whlnit will be-
of waler K. the water being de,ep eoough to rife at Icaft
as
hi~h
as from A to L. The valve
a
on the moveable
bueket
a,
and tbe valve
h
on the fixed box H, ('.hicb
box quite fills tbe bore of [he pipe or barrel at
H)
wiJl
eaeh lie clofe, by il! own weight, upon the hule io [he
bueket and box, unlil the engine begins tO work. Tbe
valves are made of brafs, and
co~ered un~erneath
wilh
lealher for c10fing [he holes the more ex,élly: and the
bueket
a
is raifed and deprttred ahernatclyby[he handle
E
and rod
D
d,
[he bueket beiog fuppofed at B btfore
the IVorkiog begios.
Take hold of the handle
E,
and thereby draw up the
bucket fromB to
e.
which will
m~ke
roomfor the air
io the pUOlp all theway below .the buckel ro dilale i[felf,
by whieh its fpring is weakróed, and Ihen its force isnot
equivalent to the weight or pretrure of Ihe outward air
upon the wacer in the l'eOel K: and therefore, a[ thefirll
llroke, the oUlward ai r will prefs Itp the waler through
the nntehed foot A. intO the 10"'er pipe, about asf., as
( ,' Ihis \Vill condenfe the rarefied air in the pipe belweeo
, and C tOIhe fanl: 11m it \Vas in before; and then, as
it! fpring wlthín the pipe is equal to the force or prdrure
of the outwJrd ai r, [he water ",ill rife no higher
by
the
firll a,oke; and Ihe valve
b,
which .'as " ifed a lilde by
Ihe dib[ion of the air inthe pipe. ",ill fall, and
nO?
th'
hole in the box H; nnd the (lt rface of [he water will
tland at _. Then, deprefs the piaon or bucket from
e
to Il , and al Ihe air in Ih. par! U
c~nnut
gel bark again
through the va!l'e
/l.
it will (as th: buckc[defcends) ,",fe
thc
v~l ve
a.
and fo make its wly Ihrough Ihe uppcr part
of the barrel
d
ioto the i'pen ai ro
uut uron
raifin~
tI\e
larga