316 SPRING. 
little by solar heat, and not at all by subterra- 
nean heat; but some, especially in the vicinity 
of active volcanoes, or in districts subject to the 
action of earthquakes, where the percolation 
proceeds within the range of the subterranean 
fires, constantly possess a high temperature ; and 
almost all springs, whether cold or hot, hold in 
solution, more or less abundantly, in more or less 
variety, and with more or less perceptibility in 
taste and colour, mineral substances derived from 
the strata through which the percolation occurs. 
See the articles Water, Minrrat Water, Irrt- 
GATION, and Fountain. 
SPRING. A mechanical contrivance for re- 
sisting percussion, regulating pressure, diminish- 
ing draught, or producing interior motion. It 
combines in a high degree strength and elasti- 
city; and may consist of elastic steel or any 
similar substance. The spring of a watch is a 
familiar instance of a spring producing interior 
motion ; and the springs of carriages, in all their 
numerous varieties, serve one or two or all of the 
three other purposes of springs. “ Springs,” says 
Mr. Giddy, “ were in all likelihood first applied 
to carriages with no other view than for the ac- 
commodation of travellers; they have since been’ 
found to answer several important ends. They 
convert all percussions into mere increase of 
pressure ; thus preserving both the carriage and 
the materials of the roads from the effect of 
blows; and small obstacles are surmounted when 
springs allow the frame and wheels freely to as- 
cend, without sensibly moving the body of the 
carriage from its place. If the whole weight is 
supposed to be concentrated on springs very 
long, extremely flexible, and with the frame and 
wheels wholly devoid of inertia, this paradoxi- 
cal conclusion will most certainly follow,—that 
such a carriage may be drawn over the roughest 
road without any agitation, and by the smallest 
increase of force. It seems probable that springs, 
under some modification of form and material, 
may be applicable with advantage to the heavi- 
est waggon.” ‘ All stage coaches, and many tra- 
velling carriages,” says Mr. Youatt, “ hang upon 
grass-hopper springs, which allow of perpendicu- 
lar without any longitudinal action. The more 
elasticity, or in other words, the more action 
there is in grass-hopper springs, the more effect 
it will produce in diminishing the draught; with 
a C spring a very contrary effect is produced. 
A carriage hung upon C springs may certainly 
be made the most comfortable to the rider; but 
all the ease that can be required, and much more 
than is found in the generality of post-chaises, 
may be obtained by well-constructed grass-hop- 
per springs, and with considerable advantage to 
the horses. The practice of loading coaches as 
high as possible to make them run light, as the 
coachmen have found by experience, is only a 
mode of assisting the springs. The mass being 
placed at a greater height above the wheels, at 
the extremity of a long lever, is not so easily 
SPRING-FEED. 
displaced laterally by any motion of the wheels, 
which, therefore, rise and fall on either side as 
they run over the stones, acting only on the 
springs, which restore the full pressure and ve- 
locity in descending, from the obstacle which 
was imparted to them in ascending, and without 
producing any sudden concussions upon the load, 
which swings to and fro with long easy move- 
ments. It is possible, also, that the weight, 
being thus swung from side to side, may, upon 
good roads, diminish the draught, as it is in fact 
generally running upon two of the wheels; while, 
in the other direction, it equally admits of the 
front and hind wheels successively passing over 
any impediment ; and yet, by the manner in 
which it is fixed upon the springs, it does ce 
admit of any longitudinal elasticity.” 
SPRING-FEED. Though the use of turnips 
in winter, and of artificial grasses on arable land 
in summer, has been carried to a high degree of 
perfection, yet a full, proper, systematic supply 
of succulent feed for young stock and for all non- 
fattening cattle, between the finishing of the tur-— 
nips and the commencement of the grasses, is 
still, in a considerable degree, a desideratum ; 
and this is what many farmers technically call 
spring-feed. Swedes have done much to afford 
the supply; but however palatable and nutri- 
tious for the main portion of stock, they entirely 
fail for the young, and do not always last long 
enough for the old. Every judicious breeder is 
desirous of training the young stock to keep 
themselves as soon as there is food of a proper 
quality available for them; and if the young 
lambs in particular are kept from green food 
until they are turned into the grass clover leys 
with their dams, there is great danger that a 
portion of them will be lost. It is generally 
desirable to keep the clover leys free at least 
until May, and long before that time the young 
stock should be trained to eat a considerable 
portion of green food. With the view of sup- 
plying this want, several plants have been culti- 
vated for early feed in the spring, with greater 
or less success, or under greater or less disad- 
vantage. The farmer who occupies a poor soil 
encounters peculiar difficulties; for lateness of 
vegetation and certain destruction of his crops 
of grass are sure to be the consequence if he 
break into them before they attain a proper 
degree of maturation, and yet he has also the 
greatest obstacles to surmount in cultivating 
any spring crop. The farmer, on the other hand, 
who cultivates rich fertile land where he has a 
deep alluvial soil, growing every crop luxuriant- 
ly, can easily free a pasture early in the autumn, 
and have it full of young grass as early as he may 
require it, and knows nothing of the difficulties 
which attend his less favoured neighbour. The 
avidity with which any new kind of forage plant 
promising early growth is tried, indicates how 
desirable a point it is to secure an early supply 
of succulent food. The crimson trefoil was tried; 
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