IRRIGATION. S&J 
Befides, there is reafon to believe that one day’s wetting 
in the lummer will, upon molt meadows, endanger the 
i'oundnefs of every fheep that feeds upon the after-math.” 
The fpring-feeding ought never to be done by heavier 
cattle than fheep or calves; for larger cattle do much hurt 
by poaching the ground with their feet, deftroying the 
trenches, and fpoiling the grafs. Mr. Bofwell like wife 
greatly recommends a proper ufe of fpring-floods, from 
'which he fays much benefit may be derived ; but, if there 
is any quantity of grals in the meadows not eaten, thel'e 
floods mult be kept out, otlierwife the grals will be fpoiled ; 
for they bring with them fuch quantities of fand and 
mud, which ltick to the grals, that the cattle will rather 
ftarve than talte it. Great quantities of egrafs, or after- 
math, are frequently fpoiled in fat countries by the floods 
which take place in the fall. In the winter-time, how¬ 
ever, when the ground is bare, the fand and mud brought 
down by the Hoods is loon incorporated with the foil, 
and becomes an excellent manure. The certain rule with 
regard to this matter is,, “Make ufe of the Hoods when 
tlie grals cannot be ufed ; avoid them when the grals is 
long or loon to be cut.” 
“ It has often been a fubjefl of difpute (fays Mr. Bof- 
weli), whether, from the latter end of autumn to Can¬ 
dlemas, the throwing a very Itrong body of water, where 
it can be done, over the meadows, is of any effential 
fervice or not? Thofe who conlider it as advantageous 
affect, that, when the waters run rude and Itrong over 
the ground, they beat down and rot the tufts of foggy or 
rough grals, fedge, &c. that are always to be found in 
many parts of coarfe meadow-ground ; and therefore are 
of peculiar fervice to them. On the other fide it is al¬ 
leged, that, by coming- in fo large a body, it beats the 
ground (in the weak places particularly) fo bare, that the 
fward is deltroyed; and alfo brings with it fuch quantities 
of leeds of weeds, that at the next hay-feafon the land in 
a 1 thofe bare places bears a large burden of weeds, but 
little grafs. 
“The general opinion of the watermen upon this point 
is, that in water-meadows which are upon a warm, landy, 
or gravelly, foil, with no great depth of loam upon them, 
rude ilrong watering, even in winter, always does harm 
without any pollible eflential fervice. On the contrary, 
cold Itrong clay land will bear a great deal of water a long 
time without injury; and' boggy, corky, or fpongy, foil, 
will all'o admit of a very large and Itrong body of water 
upon it; provided the drains are made wide and deep 
enough to carry it off, without forcing back upon the 
end of the panes. The weight and force of the wa¬ 
ter vaftly aliifts in compreiling thofe foils, which only 
want fohdity and tenacity to make them produce great 
burthens of hay; nothing, in their opinion, corrects and 
improves thofe foils fo much as a very Itrong body of 
water, kept a confiderable time upon them at that fea- 
fcn.’’ 
Notwithftanding the above reafons, however, Mr. Bof- 
well informs us, That he has doubts upon the fubjefl; 
nor can he by any means acquiefce in this opinion, unlefs 
by rude Jirong waters he is permitted to underftand only 
rather a larger quantity of water conveyed over the land 
at this early i’ealon than ought to be ufed in the fpring 
or l'ummer; unmanageable waters he believes always hurt¬ 
ful. “It may be proper juft to add (continues he), that, 
as foon as the hay is carried off the meadows, cattle of 
any fort except lheep may be put to eat the grafs out of 
the trenches, and what may be left by the mowers. This 
perhaps will laft them a week ; when the water may be 
put into the meadows in the manner already deferibed, 
taking care'to mow the long grafs which obftructs the 
water in the trenches; and this mowing is belt done when 
the water is in them. Let the weeds, leaves, &c. be 
taken out and put in heaps, to be carried away into the 
farm-yards; examine the trenches, make up the breaches, 
&c. take particular care that the water only dribbles over 
every part of the panes as thin as poffible, this being the 
warmeft feafon of the year. The fir ft watering fhould 
not be fuffered to laft longer than two or three days be¬ 
fore it is ftiifted off (and, ii the feafon be wet, perhaps not 
fo long,as warmth feems to be the greatelt requifite, after 
the land is once wet, to Hlfift vegetation) to another part 
or meadow beat cut by the cattie, by this time fit to take 
it. Do by this meadow exattly the fame, and fo by a 
third and fourth, if as many meadows belong to the oc¬ 
cupier. Obferve at all times, when the water is taken 
out of a meadow, to draw up the drain-ftuice hatches 5 
as, without doing that, watering is an injury. By the 
time that three or four parts are thus regularly watered* 
the firlt will have an after-math, with fuch rich and beau¬ 
tiful verdure as will be aftonilhing ; and both quantity 
and quality will be beyond conception better than if the 
lands had not been watered. 
“ Hence we fee why every perfon fhould if poffible have 
three or four meadows that can be watered ; for here* 
while the cattle are eating the firft, the i’econd is growing* 
the third draining, &c. and the fourth under water.” 
The irrigation of lands in China is reduced to a fyftem, 
and is confidered as a leading principle of agricultural 
fkill. Befides the methods of lifting and conveying water 
already mentioned under the article China, vol. iv. p. 487* 
another, more effeflual and ingenious, is their chain- 
pump. The machine of that name, fo common now in 
an improved ftate on-board of Englilh fliips of war, differs 
principally from the Chinefe pump, in the circumftance 
of the European pump being worked through cylindrical 
chambers, whereas in China they are univerfally fquare. 
Moll eaftern nations feem to have been acquainted at,an 
early period with the machine for railing water, known 
by the name of the Egyptian wheel , which was however 
unknown in Europe till the Saracens introduced it into 
Spain, in an imperfect ftate, and under a very awkward 
form ; being little more than wifps of hay tied to a rope 
which turned upon a wheel; one part of which being im- 
merfed in the water, each wifp imbibed a portion of that 
fluid, and di(charged it at the upperfurface of the wheel; 
but the Chinefe pump confifts of a hollow wooden trunk, 
divided in the inlide along the middle by a board into 
two compartments. Flat and fquare pieces of wood, cor- 
refponding exactly to the dimenfions of the cavity of the 
trunk, are fixed to a chain which turns over a roller or 
fmall wheel placed at each extremity of the trunk. The 
fquare pieces of wood fixed to the chain move with it 
round the rollers, and lift up a volume of water equal to 
the dimenfions of the hollow trunk, and are therefore 
called the lifters. The power ufed in working this ma¬ 
chine is applicable in three different ways. If the ma¬ 
chine be intended to lilt a great quantity of water, feve- 
ral lets of large wooden arms are made to project from 
various parts of the lengthened axis of the rollers, over 
which the chain and lifters turn. Thofe arms are lhaped 
like the letter T, and made round and frnooth for the 
naked foot to reft upon. The axis turns upon two up¬ 
right pieces of wood, kept fteady by a pole llretched 
acrofs them. The machine being fixed, men, treading 
upon the projecting arms of the axis, and fupporting 
themfelves upon the beam acrofs the uprights, communi¬ 
cate a rotatory motion to the chain, the lifters attached 
to which draw up a constant and copious ftream of water. 
This manner of working the chain-pump is illuftrated at 
fig. 1 in the annexed Engraving; and is applied to the pur- 
pofe of draining grounds, transferring water from one pond 
or ciftern to another, or railing it to fmall heights out of 
rivers or canals. Another method of working this ma¬ 
chine is by yoking a buffalo or other animal to a large 
horizontal wheel, connected by cogs with the axis of the 
rollers, over which the lifters turn. A fmall machine of 
this kind is worked merely by the hand, with the alfift- 
ance of a trundle and fimple crank, fuch as are applied to 
a common grindltone, and fixed to one end of the axis of 
the chain-pump. This laft method is general throughout 
the empire. Every labourer is in poffeflion of . fuch a 
portable 
