4 FARMERS BULLETIN 880. 



Crocks with straight sides are frequently sold with glazed earthen- 

 ware tops. These tops or covers increase the cost of the genera- 

 tors and, furthermore, are useless for fumigation purposes. There- 

 fore, when generators are ordered it should be indicated that tops 

 are not desired. 



MISCELLANEOUS REQUIREMENTS. 



Correct scudes or balances, reading in tenths of an ounce, are con- 

 venient for accurate work. An 8-ounce graduate is desirable for 

 measuring the acid and water. To avoid splashing of the acid it 

 should not ho. poured from a carboy or bottle into the graduate but 

 should be transferred to a porcelain ])itcher, from which it may be 

 poured with safety. It is well to have on hand a supply of small 

 bags in wliich to place the cyanid. 



PREPARATION OF GREENHOUSE FOR FUMIGATION. 



As a preliminary to fumigating the greenhouse it is essential that the 

 exposed glass surface be examined carefully and all broken glass re- 

 placed. AH cracks should be closed thoroughly. The ventilators — 

 both side and top, where possible — should be so arranged that they can 

 be opened from the outside of the greenhouse upon the completion of 

 the exposure. This can be accomi^lished by disconnecting the 

 "machine," or gear, of the top ventilators and attaching to the cen- 

 tral ventilator shaft (.see figs. 1 and 4) an arm (a or h) which can be 

 controlled by a cord oi wire which extends through the side of the 

 greenhouse. The gears on the side ventilators may be disconnected 

 so that the sash may be opened from the outside. If only one 

 ventilator can be opened, it is preferable that it be the one on the 

 roof of the greenhouse. 



Fig. 1. — Methods of attaching rod and cord (a, I) to ventilator shaft of greenhouse so that the ventilators 

 can be opened from the outside after fumigation. 



