��Popiihir Science Monthly
��Exit the Dinner-Bell; Enter the Flashing Mirror
FARMER'S \vi\'cs in the great south- west, where ranches are miles in- stead of acres in extent, have a novel means of signaling the men in the field. Flags, bells and horns are used to an- nounce dinner, but where the distance is too great these means fail, and the farmer's wife re- sorts to a mirror and the heliograph method.
"On a tour of inspection," writes a telephone man, "I happened to stop at a farm- house for dinner. The woman who came to the door said that she would call her husband. Upon inquiring where he was she handed me a pair of binoculars and pointed down the valley. I looked and could see the big caterpillar pulling two headers. As it rounded the end of the cutting on its return trip the woman flashed a mirror into the eyes of the dri\'er three times. As I watched I could see the machine come to a stop and presently I saw him coming up the road in his runabout car. He was working five miles away. The woman explaineil that she learned this heliograph method from the Indians." But suppose it's cloudy?
���Calling the men to dinner by signaling with a mirror. But what if it rains?
��Why You Can See Two Sides of a Thing at the Same Time
IF you spin a quarter and watch it you will see both .sides of the coin at the same time. This is exi)lained by the fact that the senses of man retain impressions a little time. It is, indeed, the explana- tion of motion-picUires. Your \-ision persists and >our percejition of objects is continued after the object itself has dis- appeared. This allows you to see two parts of a thing — even such ojipositcs as the front and back — simultaneously.
��War will Diminish the Stature and Vigor of the Human Race
most striking end effect of ir is race deterioration," com- ments Dr. (Jeorge W. Crile, a member of the American Ambulance who served during the first stages of the conflict abroad ("A Me- chanistic View of War and Peace," T h e M a c m i 1 1 a n Company).
"The effect of war on the race is seen in the effect of emigration on New England. In stature, in energy, and in enterprise, the New England farmer has deteri- orated by losing so many of his fit- test sons. It has been stated that Napoleon short- ened the stature of the French by several inches. The human animal is not unlike other animals — no one breeds from scrub stock. This war will diminish the stature and vigor of the human race to the extent that the killed were larger and stronger than those who remained at home.
"The birthrate at the end of the war will be changed. It will be increased among the victors, decreased among the vancjuished. In this respect man reacts like animals. Animals brcetl best amidst plenty, less when food ami shelter are inadequate, and least of all w hen harassed in captivity."
��Plants on National Forest Ranges Which Kill Cattle
��API'ROXIMATELY eighty-f . cent of the losses of cattle on the National Forest ranges clue to poisonous plants is caused b\- tall larkspur. Death canias, lupine, lamel, sneeze weed, and rubber weed are responsible for sheep losses from such cause, while loco weed is the principal poisonous plant affecting horses which graze about freely.