NINTH ANNUAL YEAR BOOK— PART XII 719 
have been depleted from the hills upon which large cities depend for 
their water supply. The cleaning away of the vegetation from the higher 
lands has left no humus to hold the Avater precipitated. Consequently the 
hard rains give rise to torrential streams which rush into the valley, 
eroding all the fertile soil and, upon augmentation from other streams 
causing floods with consequent enormous losses to life and property. 
Then the hills become barren, the springs cease flowing, the rivers sub- 
side into sluggish streams, wells and underground current that formerly 
flowed constantly, diminish in volume and flow only intermittently or 
not at all. 
Forestry is vitally associated with irrigation. All waters used for this 
purpose in the west are obtained from the mountain sides. The coniferous 
trees growing on the mountains shelter the snow from the sun and hold it 
until late spring or summer, then slowly melting it feeds the streams 
from which water is taken for irrigation. Where the trees have been 
cut, the wind blows the snow from the mountains into the valleys where 
the sun rapidly melts it. The water thus formed rushes off in early 
spring in torrents. When the farmer wants water for irrigation he may 
find it in the Gulf of Mexico. 
When the pioneer first broke the western prairies he had little trouble 
with insects. Large areas were cleared and planted to agricultural crops. 
The equilibrium of nature was disturbed, the plants upon which the in- 
sects had been feeding being killed by the plow and harrow and these in- 
sects turned to cultivated crops. As large areas were planted to corn and 
other cereals, the enemies of these grains swarmed in to feed upon them. 
With the destruction of the woodland inevitably followed the slaughter of 
the birds which the trees sheltered. Without protection from the birds of 
prey and the gun of man these insect eating birds were seriously depleted 
in numbers. In many cases they have become extinct or have left their 
old haunts entirely. Then, with their foes gone, the insects multiplied at 
an enormous rate and devastated the farms. Hence, the farmer is now 
troubled by hundreds of species of insects which annually cause a loss of 
about $700,000,000. 
THE CATALPA FROM A SEED TO A FENCE POST. 
M. C. BURXET, ALLERTOX, lOAVA. 
(Before the Wayne County Farmers' Institute.) 
The farmers of the middle west are facing a post famine. The second 
growth of native timber, where available, is poor post material, and 
almost all of the matured trees have been used. The present high priced 
labor and the expense of transporting post material from a distance makes 
it an item of expense to replace posts every few years. A solution of 
the problem is to plant a growth of catalpa speocia, or hardy catalpa. This 
tree is of quick growth and the wood is light, strong and durable. It 
is a native of the Wabash and its tributaries in Indiana and southwest. 
More than eighty years ago in an address at an agricultural fair in Cin- 
cinnati, Gen. Harrison gave an account of a catalpa log over a small 
