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The James Ventilator with Revolving Hood 



(PATENT APPLIED FOR) 



The revolving hood principle adds greatly to the ventilator's capacity to 

 remove foul air. 



A study of Fig. 2, page 268, will make clear how the air in one-half 

 of the outtake flue is removed through the usual space between louvres (points 

 "M" and "B"), while the air from the other half of the outtake is removed 

 through the additional outlet space of the revolving head at the point marked 

 "FF ". In other words the outlet space has been enlarged as compared with 

 the ordinary type of ventilators. 



The James ventilator with revolving hood also takes advantage of the 

 power of suction — it helps pull foul air out of the barn and brings fresh air in. 



The top of this Ventilator (the dark portion of Fig. 4) turns on a hardened 

 steel point, like a compass ("K" Fig. 2). The vane "B" (Fig. 4) keeps 

 the opening "C" (Figs. 2 and 4) always toward the wind. 



The tapering construction of the "intensifier" ("C-A," Figs. 2 and 4) 

 "speeds up" the wind as it passes through, so that it leaves "A" at high veloc- 

 ity. This creates suction in the vicinity of "FF" (Fig. 2) exerting a powerful 

 pull on the air in the outtake flue. 



An Interesting Test — Try It 



Take a sheet of paper about the size of this page. Roll it in the form of 

 a cone having a diameter of about one-fourth inch at the small end and one 

 inch and a half at the big end. 



First, put the little end in your mouth and blow, holding one hand about 

 six inches in front of the big end. The current of air can hardly be felt. 



But now turn the paper cone the other way around. Put the big end in 

 your mouth and blow, holding one hand about six inches in front of the little 

 end. A strong current of air will be felt. 



In just the same way, the wind passing through the tapering intensifier in 

 the James Ventilator with revolving hood increases in speed and leaves with 

 high velocity at point "A" (Fig. 2). 



If you are a smoker, here is another easy experiment which will further 

 illustrate this suction principle. 



"Hit up" your pipe or cigar until you have a good thick cloud of smoke. 

 Then pucker your lips and blow vigorously into the center of the smoke cloud. 

 Not only the smoke directly in the path of the current of air is removed, but 

 the surrounding smoke is also sucked into the current and carried away. 



Just so the higher velocity at point "A" creates suction, carrying the sur- 

 rounding air with it. As this surrounding air is warm moist air from the outtake 

 flue, the air removed by the suction is constantly replaced by more air from the 

 flue, thus speeding up the outflow of foul air and increasing the amount removed 

 in a given time. 



