"^B^ JAOQGS X^&S: 271 



It IS very much the same prmciple as that of the ejector in a steam engme. 



Another illustration in point is the suction created by the rapid movement 

 of a train or an automobile. Watch an express train passing by and you will 

 see a cloud of dust and light weight-refuse, such as scraps of paper following. 



In the same way the velocity of the air leaving the intensifier at "A" carries 

 the surrounding foul air with it. 



The foul air removed from the barn is, of course, at once replaced with 

 pure air from out of doors, through the fresh air intakes. 



The slightest breeze will turn the ventilator top, and a very light breeze 

 blowing through the intensifier will create some suction. 



Aviators have found that even when there is no wind or air movement 

 apparent to a man on the ground, there are nevertheless currents of air in con- 

 stant motion. Hence the James Revolving Hood Ventilator is always at 

 work helping to remove foul air. 



Every system of ventilation depends for its efficiency on the thoroughness 

 with which foul air is removed and fresh air brought in to take its place. 



The motive power on which other systems depend for a continuous upward 

 current in the foul air flues, is a difference in temperature between the air in the 

 stable and the air out of doors. 



Or in other words, they depend upon the air in the stable being lighter 

 (warmer) than the outside air. 



The air in the stable being warmer, the air at the inside opening of the 

 outtake flue will be lighter than the air outside and will rise. 



The upward movement of air in the flue started in this manner is assisted 

 to some extent by "aspiration" — that is, by the wind blowing across the top 

 of the flue; just as a chimney has a stronger draft when the wind is blowing. 



But where dependence is placed wholly on the motive power furnished 

 by the warmer (lighter) air and by the wind blowing across the top of the 

 outtake, the ventilating system will sometimes not operate satisfactorily in the 

 warmer weather and under certain atmospheric conditions. 



The James Improved Ventilating System is more efficient because it not 

 only uses the same motive forces employed in other systems, but it adds the 

 additional motive power of suction, applied at the outlet of the foul air flue. 



It removes a greater quantity of foul air in a given time and makes the 

 ventilation more uniformly successful under all conditions. 



The James Ventilator, as before stated, offers little hindrance to the out- 

 flow of air, the air current having to make but one turn and that of large radius 

 much less than a right angle (see "GG" "HH," Fig. 2). 



The deflector in the shape of a half cone "HH" (Figs. 10 and 4) prevents 

 outflow of air in that half of flue interfering in any way with the other half. 



The little wind which can blow in, when an upward slant of wind strikes 

 the ventilator must blow directly through and out (see D-G-G, Fig. 10). 



