Botany (Civil Service Examination), Questions and Answers, GK for UPSC, Bank PO & All Exams
1. World Geography -Test-01
2. World Geography -Test-02
3. World Geography -Test-03
4. Geography of India -Test-01
5. Geography of India -Test-02
6. Geography of India -Test-03
7. Geography of India -Test-04
8. Geography of India -Test-05
9. History of India - Test - 01
10. History of India - Test - 02
11. History of India - Test - 03
12. History of India - Test - 04
13. History of India - Test - 05
14. History of India - Test - 06
15. History of India - Test - 07
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Top Fishes of India
101 Strangest Laws Around the World
Most Popular Animals
Labor saving Devices
Man's Way of Helping Himself
To primitive man belonged more especially the arduous tasks of the out-of-door life: the clearing of paths through the wilderness; the hauling of material; the breaking up of the hard soil of barren fields into soft loam ready to receive the seed; the harvesting of the ripe grain, etc.
The more intelligent races among men soon learned to help themselves in these tasks. For example, our ancestors in the field soon learned to pry stones out of the ground rather than to undertake the almost impossible task of lifting them out of the earth in which they were embedded; to swing fallen trees away from a path by means of rope attached to one end rather than to attempt to remove them single-handed; to pitch hay rather than to lift it; to clear a field with a rake rather than with the hands; to carry heavy loads in wheelbarrows rather than on the shoulders; to roll barrels up a plank and to raise weights by ropes. In every case, whether in the lifting of stones, or the felling of trees, or the transportation of heavy weights, or the digging of the ground, man used his brain in the invention of mechanical devices which would relieve muscular strain and lighten physical labor.
If all mankind had depended upon physical strength only, the world to-day would be in the condition prevalent in parts of Africa, Asia, and South America, where the natives loosen the soil with their hands or with crude implements, and transport huge weights on their shoulders and heads.
Any mechanical device, whereby man's work can be more conveniently done, is called a machine; the machine itself never does any work - it merely enables man to use his own efforts to better advantage.
FIG. - Prying a stone out of the ground.
FIG. - The wheelbarrow lightens labor.
FIG. - Rolling barrels up a plank.
FIG. - Crude method of farming.
FIG. - Primitive method of grinding corn.
FIG. - Separating rice grains by flailing.