CONSTRUCTION OF VENTILATORS AND FLOORS 113 



Ohio, Prof. F. M. Webster has fo^nd slats raised 

 eight inches or a foot from the ground preferable to 

 the ground floor. Where it is intended to drive 

 wagons into the house the ground floor will answer 

 all purposes. With a slat floor the gas is generated 

 beneath, and spreads almost instantly throughout the 

 space between the ground and the slats, passes up- 



FIG. 67 DIAGRAM OF GENERATOR AND SECTIONAL VIEW 

 OF FUMIGATORIUM. (AFTER WEBSTER) 



ward through the trees, and promptly reaches every 

 part of the apartment. 



The generator, shown in Fig. 67, consists of an 

 earthen jar of the requisite capacity, a, fixed to the 

 end of a plank, b, and just in front and between two 

 posts, cc t through which passes a roller, d t and to 

 this last is fixed a pan, , with back and sides but 

 no front, one end of the roller projecting beyond the 

 post with a small iron bar or heavy wire, /, passing 

 through it, and being fixed and bent at either end, the 

 whole having much the appearance of a windlass with 

 pan, e, added. The sulphuric acid and water are 



