LUNGS OF THE HORSE. 289 



withers backwards, then extend diagonally to the 

 elbow, and then upwards to the junction of the neck 

 with the breast. 



Let the reader turn to the skeleton on page 3, 

 and then draw a line from the top of the rib just 

 below' c, and continue it diagonally to I. This line 

 will represent the ' sound-board ' of the harp, the 

 ' pillar ' occupying the front of the chest, and the 

 4 neck ' running tinder the spine. Nearly the whole 

 of the cavity of the ribs in front of the ' sound-board ' 

 is filled with the lungs. 



So enormous a structure indicates that the supply 

 of fresh air ought to be correspondingly great, and 

 that there shall be means of escape for the air which 

 has been breathed, and in consequence is not only 

 useless for respiration but absolutely poisonous. 



Yet, in how few stables do we find even an approach 

 to systematic ventilation? The reason is evident 

 enough. In the first place, a stable is considered so 

 simple an edifice that any one can build it. Ac- 

 cordingly we find that, as a rule, the architecture 

 of a stable is about on a par with that of a house 

 which a child builds with his box of wooden 

 bricks. 



The typical stable is an oblong box of bricks, 

 divided into two storeys, the upper being used as a 

 hay -loft, and connected with the stable by a ladder 



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