about 1°56 of respectively carbonic oxide, nitro- 
gen, and hydrogen; so that, in all the approaches 
of water to plants, whether through the air or 
along the surface of the earth, or through the 
interior of the soil, it acts as a mighty, greedy, 
and general forager on their behalf, and con- 
stantly comes laden to them with a variety of 
the most enriching spoils. In its capacity of 
general menstruum, general solvent, and grand 
constituent of juices, also, it is a mighty and 
essential modifier of all other natural agencies 
upon plants, lubricating all the organic energies, 
sustaining all the absorptive, inhalent, and ex- 
halent functions, assisting every internal act and 
process of chemical transmutation, attempering 
the outward play of light and heat and weather, 
and resisting all mischievous effect from excess 
of calorific, absorbing, or caustic agencies. The 
reasons, therefore, are strong and many why 
field plants are injured or destroyed by droughts, 
and why garden ones are benefitted by artificial 
waterings. Yet the diffusion of water as vapour 
through the atmosphere when it loses its liquidity 
and rises out of the soil,—the accumulation and 
abundance of it in the former state proportion- 
| ately to the decrease and scarcity of it in the 
latter,—and the adaptation of it as a vapour, to- 
| gether with all the gases which it has absorbed, 
to be bibulously inhaled through the stomata of 
plants,—are to the full as wonderful as any of its 
other properties, and beautifully supplement the 
amazing powers with which the Creator has en- 
dowed it for supporting vegetable existence. 
“The quantity of water which exists in air as 
vapour,” remarks Sir Humphrey Davy, “ varies 
with the temperature; in proportion as the 
weather is hotter, the quantity is greater. The 
leaves of living plants appear to act upon the 
vapour in its elastic form and to absorb it. Some 
vegetables increase in weight from this cause, 
when suspended in the atmosphere and uncon- 
nected with the soil; such are the house-leek, 
and different species of the aloe. In very intense 
heats, and when the soil is dry, the life of plants 
seems to be preserved by the absorbent power of 
their leaves; and it is a beautiful circumstance 
in the economy of nature, that aqueous vapour 
is most abundant in the atmosphere when it is 
most needed for the purposes of life, and that 
when other sources of its supply are cut off, this 
is most copious.” 
The command of a sufficient supply of water 
for all the uses of the farmery and of live stock, 
is essential to agriculture, and was formerly a 
great desideratum throughout some extensive 
districts in Britain. In the low tracts of Lin- 
colnshire, water free from brackishness and per- 
fectly fit for drinking is so scarce that carts are 
sent for it to the distance of several miles,— 
sometimes even to the distance of 16 or 17 miles; 
in the wolds of Yorkshire, previous to the in- 
vention of the improved mode of making arti- 
ficial ponds, instances were frequent of numbers 
er 
of animals perishing from thirst; and in Hamp- 
shire, from the long continuance of dry weather 
during the autumnal months, the wells became 
so exhausted, that great labour and expense 
were incurred in supplying the family and stock, 
by means of water-carts. To avoid the risk of 
such serious misfortunes, it was anciently the 
practice, for the conveniency of having water, 
to erect farm-buildings in low grounds, near 
brooks or rivers; but on this plan the house be- 
came damp, the grain, from the moisture of the 
atmosphere, was frequently injured, and, from 
the vicinity of the water, accidents of various 
descriptions frequently occurred. When the ad- 
vantages, therefore, of having a house and offices 
in the centre of the farm, and rather on an ele- 
vated situation, came to be generally understood 
and admitted, methods were adopted for obtain- 
ing supplies of water from the roofs of the farm- 
buildings, from natural springs, and from wells, 
artificial ponds, and artificial rills. The buildings 
and yards of a farm are supposed to receive rain 
sufficient, if duly collected, to supply both the 
family and the cattle of the place for a consider- 
able part of the year; and ponds, where necessary, 
may be made in any situation, at a very small 
expense, for the remainder. See the article Tanx. 
Where natural springs occur, they will generally 
furnish a sufficient supply for family use; but 
they are seldom adequate to the necessities of a 
great farming establishment. See the article 
Spring. In Middlesex and Surrey, the farmers 
have dug to the depth of from 100 to upwards of 
560 feet, before they could procure water; in 
Essex they have been obliged to go as deep as 
500 feet to obtain water of a good quality ; and, 
in Hampshire, they have likewise dug from 300 
to 400 feet in depth, through dry, cracked, or 
fissured chalk rock. See the articles Wren and 
Artesian Wett. In several parts of England, | 
as in Hampshire, in Lincolnshire, and in Norfolk, 
artificial ponds were long ago formed with varied 
skill and success. In Gloucestershire, they were 
made either of a square or of a circular shape, 
and generally so situated as to furnish a supply 
to four fields. Three layers of clay, free from 
the smallest stone or gravel, were so worked in 
as to form an impenetrable cement; and the 
whole was afterwards covered with sand and fin- | 
ished with pavement. In Derbyshire, artificial 
“meers,’ or cattle ponds, are made in dry rocky 
pastures, with great success. Having selected a 
low situation for the purpose, they deepen it ten 
or twenty yards acrossyand spread over the whole 
excavation a layer, about five inches thick, of 
refuse slaked lime and coal cinders; they then 
spread, trample, and ram down, a stratum of 
well-tempered clay, about four inches thick; 
and upon this they place a second bed of clay, 
in a similar manner, of the same thickness; the 
whole of the bottom and edges of the meer is 
then paved with rubble stones; and small rub- 
ble stones, several inches thick, are spread upon 
