Human physiology : designed for colleges and the higher classes in schools and for general reading . THIRD KIND OF LEVER. a lever of this kind. This form of lever is more frequentlyused than the other forms in the human body. We have anexample of it in bending the forearm upon the arm as seen inFig. Ill, in which 1 is the bone of the arm; 2, the bones ofthe forearm ; 4, the muscle which bends the forearm upon thearm; 5, its double headed attachment above; and 6, its at- 200 HUMAN PHYSIOLOGY. Two objects aimed at in muscular action ; quickness and power. FIG. tachment to the ulna, the chi
Human physiology : designed for colleges and the higher classes in schools and for general reading . THIRD KIND OF LEVER. a lever of this kind. This form of lever is more frequentlyused than the other forms in the human body. We have anexample of it in bending the forearm upon the arm as seen inFig. Ill, in which 1 is the bone of the arm; 2, the bones ofthe forearm ; 4, the muscle which bends the forearm upon thearm; 5, its double headed attachment above; and 6, its at- 200 HUMAN PHYSIOLOGY. Two objects aimed at in muscular action ; quickness and power. FIG. tachment to the ulna, the chief bone of the forearm. In thiscase the fulcrum is at 8, the joint of the elbow, the weight isthe hand with whatever it holds, and the power is applied atthe point where the tendon is fastened to the ulna, that is, as inthe case of the ladder, between the fulcrum and the muscle which straightens the forearm upon the arm isrepresented at 1. I shall remark upon this in another con-nection. 299. In the management of the three kinds of levers thereare two different objects aimed at under different object is to move a great weight with a small quickness is not aimed at, but the weight is moved other object is to move the weight quickly, an object in-consistent with the moving of any very heavy weight. Whenthe object is to move a heavy weight slowly, the lever is somanaged as to get a good purchase, as it is expressed. Thusin the case of the lever of the second kind, Fig. 108, if theweight be a heavy one, the po
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Keywords: ., bookauthorhookerwo, bookcentury1800, bookdecade1850, bookyear1854
