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SHELTERBELTS AND WINDBREAKS. 
The terms “ shelterbelt ” and “ windbreak” are often used inter- 
changeably. When distinguished, shelterbelt is applied to trees 
planted in groups of considerable size, while one or two rows to 
check the wind is called a windbreak. Since this discussion applies 
equally well to both shelterbelts and windbreaks, the latter term is 
chosen for the sake of simplicity. 
In an open country of high winds, nothing adds more to the com- 
fort of existence than a protecting belt of trees about the home. 
Whether the wind be the hot one of summer or the snow-laden blast 
of winter, its force is spent on the trees, and the house within is 
not swept by every passing gust. Orchards need windbreaks to 
save them from injury in the gales that accompany summer storms 
as well as to protect them from ordinary winds throughout the 
year. Gardens are more successful when surrounded by trees. Wind- 
breaks benefit animals as much as their owners. 
Any species that is adapted to the region and suits the taste of 
the planter may be used for a windbreak. Where they will succeed, 
evergreens are desirable, since they afford better winter protection 
than the deciduous species. The man who wants a windbreak, how- 
ever, does not care to wait for slow-growing trees. The Austrian and 
Scotch pines grow quite rapidly and serve the purpose well. A 
windbreak consisting of a single row, to be effective, should be of 
a densely growing type that branches close to the ground. For low 
breaks of this character the Russian mulberry and Osage orange 
are excellent. The tamarix, while more like a large shrub than a 
tree, does well for low windbreaks around garden patches and similar 
areas. It is easily propagated by cuttings, grows rapidly, and is 
quite hardy. The cottonwood is the common tree used for wind- 
breaks in the valleys. 
One of the most important functions of the windbreak is the saving 
of soil moisture within the protected area. In the Monthly Weather 
Review for September, 1888, were published the results of experiments 
made by the United States Signal. Service to determine the effect of 
the rate of wind on evaporation from a water surface. The experi- 
ments were made with a Piche evaporometer, under constant condi- 
tions of humidity and temperature. The figures obtained are given 
in the following table, in which wind velocity is expressed in miles 
per hour and the unit of evaporation is that in a calm: 
7s Evyapo- ATi | Evapo- | 
Wind’ eration! ! Wind: _ tation. 
Ril accaes 20 5.7 
10 aF8 25 6.1 
15 4.9 || 30 6.3 
(Cir. 161.] 
