452 MUSCULAR MOTION. 



would seem to be necessary to insure, that the portion of the body, 

 which is the great outlet of the respiratory organs, shall be above the 

 surface. 



The movements, adapted to the progression of the body, are to be 

 acquired in the same manner as a child learns to walk ; proficiency in 

 this, as in every thing else, being the result of practice. 



Swimming nearly resembles leaping, except that the effort in it does 

 not take place from a fixed surface. Both the upper and lower extre- 

 mities participate in it. Whilst the former are brought to a point 

 anterior to the head, and form a kind of cut- water, the lower extremities 

 are drawn up, and suddenly extended, as in leaping. The water, of 

 course, yields to their impulse ; but not as rapidly as it is struck, and 

 hence the body is projected forwards. The upper limbs are now sepa- 

 rated, and carried circularly and forcibly round to the sides of the body, 

 by which the impulse is maintained; the legs are in the meantime 

 drawn up; and, by a succession of these movements, progression is 

 effected the hands and feet being turned outwards to present as large 

 a resisting surface as possible. The chest is, at the same time, kept 

 dilated, to augment the bulk of the body, and, of course, to render it 

 specifically lighter, and the head is raised above the surface to admit 

 of respiration. This action is analogous to that of the propulsion of a 

 boat by oars. The body resembles the boat ; and the upper and lower 

 extremities are the oars or sculls. 



The practised swimmer can execute almost as many movements in 

 the water as he can on land. 



e. Flying. 



If the human body sinks in the water, how little can it be susceptible 

 of suspension in the air by its own unassisted muscular powers ! This 

 is a mode of progression which is denied to man; and accordingly, 

 most of the attempts at flying, since the mythical exploits of Daedalus 

 and Icarus, have been confined to enabling the body to move from one 

 place to another by means of ropes and appropriate adjuncts. Years 

 ago, a native of this country exhibited a curious variety of progression, 

 at Dover, England. He was called the "flying phenomenon;" and his 

 plan, so far as we can recollect, was to have a rope extending from the 

 heights to the beach beneath, along which he descended by means of 

 rings attached to different parts of his person, which had the rope pass- 

 ing through them. 



The sources of difficulty, in flying, are; the great weight of the 

 body, and the insufficient force which the muscles are capable of exert- 

 ing. It is by no means impossible, however, that by some contrivance, 

 of which the lightest gases might form a part, and by an imponderous 

 apparatus, which would enlarge the surface of the upper extremities, 

 progression, in this manner, might be effected; but to a limited and 

 unmanageable extent only. 



f. Other Varieties of Muscular Action. 



Connected with this subject we may refer briefly to some varieties 

 of muscular action, the nature of which will be easily intelligible. 



