1000000030

A N

~",,'us ¡or~s

anll O,eh cs, by 1.,i"S pla,eJ over

l~em.

í" ·II"OK.

Se~

Hilo ;; .

t \'\

\D \ ,

or •

" :'.1'

1-',

,"C:,

e~¡:r.r,,·!

m ·'l of

N,mh

.\",~, i·;.I. h~l"h\:.1

[.0.,

l'tI. }j,il.l'" alld Ihc

B, ililh ':JI,,"íes on

!lu

Iflo'; h ..

on lilc "' !1h; oy

lh~

¡¡\CI

Li'WI ~'I)I\'1

Ihe

l't'CIUJis,

or ¡¡"e

lod,an

nJl""'~,

lhe IIIII'J., ,11,,1IIIJnJi\ l,ke5, on the ed l! and

f"",h;

.1II.!

unku~v.

nlaods, on lile wdl. /ts dl¡ f

(ywn is

~chcc.

í.\ NAL

DI' wnn¡:¡ni.:.1tim,

an anificilJ cut in lhe

g,~uod,

bpplicJ wilh wa"" flOm ,ivees,

fpein~s,

&c.

;n o../a lo

m.ke

a n.,igob!c communie.!l,on

~ct\li · t

one pl.lce and

anllth~e.

The pJl tiruln

O?~ellionl

needfary for making aro

¡ifim l """ g.!lions d,'peud upvn a numbee of .:ieeum·

fiJtlces. The litu"",n of lhe glOUtlU; lhe vieinity

or eoont'éllOn with m'ers; the eafe

diflicu!t), \l ith

wh:,¡' a peopee

quaOli~y

01'

Wller eJn be ob,."nld ;

th& .1I1'! many olher eircumOances nrrdraeily produce

~eeal l'4l

:elyin toe O,

Ul~ure

of Jltifiei,1n"'igJlIOnS, and

,ur.,~ent

'1<

diminiO,

¡h~

labo,;r allJ ex"encc of exe·

ruung lhcm. When Ihe geo\'nd is naturally ItI'el,

and unconnncc'\cd \l il!! ei,t,s, lhe

e~eelltion

is ealy,

;,nJ lhe n."'igJtion is nl't !i¡ble 10 be uillllrbed by

!loco , ; ¡'Ut, IIhell lhe grulllld " fes aod

f~l!s, ~nd

can·

no: be

r((llI~d

tO a

I~"d,

artificial melhuds of

rJ,{ing and lo,!cring rdfds muH oc empluyed;

IlIeh

I.lewife rdry aeeordiog

circt:mllanees.

k:r:¿ of lempow y P.uiees are

fUIl1Cli.l1~s

emFloyed

f~r

r."r,"J

b~at¡

om f.

.I1s

or 01011s :nrivers by a lery

r,ill"I~

opmllon. Til'O rons or pillars 01' mafon·

\I'"~,

ilh groc"es, are lixld, one on eaeh lunk 01lhe

(¡rer,

fome di!lan:ebelow the {ho.1. Theboal ha·

v:n~

p.{i(d ,hefe polls, planks are lel clown dCrcfl lhe

TII·.,r by pullies iOlo Ihe grooves, by

\l'hi~h

Ihe wmr

is damrued up tO a proper

h~ighl

fo: allowins lhe boat

to pa:s

I;P

lhe ,iver om the 010"1.

The Duteh and Fleemings al Ihis da

Cumclim.s

",hen oJ{lruaed by eaícades, form an inclined plane ur

rnlling.bridge upon dry land, alongH whieh lhw vef·

fels

JrC

ura\\'n from lhe ,irer below the eafeade iOlo

Ihe river abuve i,. This, il is

f.iu

, was lheoolyme·

Ihod wplo)'ed oy '¡he ane,ents, and is lIill nfcd hy lhe

('h:n&, who are

l~iJ

10 be enti rely ignorant

01'

the

tw 'tre nnd milily of locks. Thefe rolling.b,idges

e1lO!ill of a

n~mbtr

of eyliodrieal rollelS \\ hich turo

c.,f'¡y on

pi'~IS,

and a mili is eonrmonly buil! near by,

fu Ihal Ihe fame machinerymal' fem ¡he doublc pur·

pofe

01'

work.ing lhc mili "nd drawing up '·c([,els.

LoCK is a bafun rlm d

Itnglhll'il~

in a rirer or

canal, lineel Wilh wnlls of

I!,a f~nl'y

on eaeh fid(', !lnll

lerminalcd by 11'10 galcs, plaeed whel'e lhere is a e/f·

r.deor naturall,dl uí d,e rOllnll ),; an'! fu eor.Orulled,

l!,all:.e bafon bcioglilled wilhWall'l' byanurpcr Ouiee

lfJ

Ihe levd uí lhe \\·'.ters above, a ve(['e1 may alcend

lhrou~h

lhe uppcr

&'lIt;

or Ih': Walcr in Ihe loek be·

in' t,dueed

lhe lel'd of lhe IV:!ler al lhe bOIlUA' of

th~

e,f.:,d:,

lh~

'LOcl may dclceod lhrounh the lower

gale

((JI' \\

Iten

lhe:

w,lIers are

l)rought

10 a

len l

'.ilher

H:,

the

2':c

011 Ihat r,de

Illdy

beeafily ureneel.

A N

RUl as lhe lower gate i, IIrainerl in proportion to ¡he

rlrplh of w,ter it fu ppollS, whcn lite perpendicular

heigh¡ of the water txeeeds

feer, more loek.

lhan Olle becorne neeeO:'ry. Thus, if Ihef,1I be '7

fm,

''''0

lo, k<

ae~

required, eaeh having 8

fcel

f.lI;

. ntl if the

f.dl

bc 26 fcel, thrce Jo, ks are neee(['ory.

e3ch having S reel 8 inehes f.u. The fide·w lis of a

loek ough¡ 10 be I'/!ry

neon~.

Where the natural

foundalion is bad. lhey fhould be founded on piJes ind

rlatforms of wtod: They {hould

lik~wir~

Oopout·

wardr. in order

refill the pre(['uee of Ihe emh feom

oehind .

Plale LX. fig. l.

perfpeélive I'iew of par! of a

can.ll

lh~

veO' I

wilhin lhe loek

e .-Fig.

Seélion of an open lock: Ihe ve(['e! L abou¡

en·

ter -Fig.

Seélion of a loek full of water: Ihe

e(['d L railecl 10 a level wi,h lhe water in lhe fupe,i·

Ilr t<n¡I.-Fig. 4'

rOl!nJ feélion of a Joek. L, a

"c([,d

in Ihe inf<tiM canal.

the undrr gale.

Ihe upper gateo G

fubtemncuus pa(['age fur

1\l ling w.Uor from the fuperior eallal run iOlO lhe

loek.

afublel raneoltS pallage for water from lh,

loe' ,

Ihe inferiur canal.

X aod Y

(fi.~.

l.)

are the two Rood.gales, eacll

whi~h

eonfills of lWO

1~a1'es,

tefling up·JO ooe ano·

lher, fo as10 fom, ao oblufe angle, in order Ihe bet·

lee¡Orefifi lheprdure of Ihe wmr. The

firll (X)

p'el'ents ¡he

w~;er:-of

lhe li'penor can.1

f?00l

falling

tOlOlhe

I~ek

.and lhe f,conu

(Y)

d.ms

up and fu·

1I.•ins Iht wa:er in lh- luek. ThdC lIood·sales ought

to be very Orong. and tO turo fredy upon their hin·

ges. In urder

n,,~e

lhem oren and P.:ut wi:h cafe,

eaeh le,lr is furniO,ed witb a long lem

Ah;

They !hould bornade vlr)' .ighl and clofe,

¡hal as !illle water

pomble may

1,,11.

By ,he

fublerr~neous

p.fiage

G H

(Iig.

2, "

)

whiehdcfeclld¡ obliquely, byopeninglhe fluiee

lhe

waler is lel

d~\\'n

from Ihe f"perior eJn.1D, intJ the

loek, where il is nopl and rctaincu by

L~e

galo e when

Ihul, lill lhe water in lhe lúek eUllles tO

on a lerel

Wilh thewater inthe

rUi'~riot

canal D; as rep,cfented,

fir.

When, onIhe (llher hand. lhe waler eon,ained

b)' Ihe lork is 10 he lel UUl, lhe pandse

mun be

fitut h)' Iwing d"wnlhe Ouiet G, the glle

mun be

airo {hUI, anJ the paO:'gc

K F

opened by raifing the

fluiee

K : A

free panage being Ihus gi"en to Ihe wa·

ter, it deCcends Ihrollgh

K F,

inlo the i"ferior canal,

untillhe

1'I~ler

in tbe loel; is on a kl',! with Ihe

lI'al~r

in lhe infcrior ean.1

I3;

ns rtpr&nlcd, fig. 2.

Now, Jel il be ,eqlli,ed 10(Jifelhe "elfel L (fig.

2.)

from lheinferiorc.nalB, tothe fUl'eriur '"1CD ; iflhe

loek happens 10befllll oi'whter.lhc

fl~i~~

mull beIhul,

¡¡nd . Ifo the gale A, and Ihe lIuiee K 0pcII«I, fu lhat •

the waler in lhe loek may run out till

is onaIcrel

Wi,h Ihe waler in lhe i"ferior "lI1al

When the

waler in lhe loek comes 10 be on a len l IVilh Ihe

\I'~lcr

al B, lhe Icaves uf lhe &"e

ale "pencd by

lhe levc,'s e

whieh is clfily perfotllltu. ,he waler

on edch fitlo of lhe g.lte bcioC in eqmhbrio ; lhe "cllé!

lhen fJils imo Ihe lock. Af,er lhis lhe gJte e, .lid lh,

!lu,ee