8 



(5) Wells and Hayman's Cotton Seed and Cotton Stick Fumigator. - 

 Mr. John Wells, Consulting Engineer to the Egyptian Government, 

 has recently submitted the plans for a machine designed by. himself 

 in conjunction with Mr. Hayman, for killing pink boll worms in 

 the bolls left on cotton sticks after the last picking by fumigating 

 them with the fumes given off by distilled cotton sticks. He remarks 

 that this method could also be used for treating cotton seed. The 

 apparatus figured consists of a vat which will hold forty tons of cotton 

 sticks after they have been chopped up into pieces not more than 

 two inches long, this chopping causing a reduction in volume to about 

 one-sixth of the volume of the unchopped sticks. Into the top of 

 this vat is led a tube from a retort in which the cotton sticks are 

 distilled, the air forced out during the process being allowed to escape 

 from the bottom of the vat. Presumably, if this machine were to 

 be used for cotton seed, considerable modifications would be made in 

 order to adapt it to the requirements of the ginnery. 



So far, however, not even a small-scale machine has been built 

 on these lines, so that it is impossible to say whether the fumes would 

 penetrate the seed sufficiently to kill the worms, or whether the 

 tarry products in the distilled gases would have a deleterious effect 

 on the germination of the seed. 



For further particulars apply to Mr. John Wells, Consulting 

 Engineer, Sharia Sheikh Abu el Sebaa, Cairo. 



HOT-AIR MACHINES. 



Before proceeding to deal with individual hot-air machines in 

 detail it will perhaps be well to discuss a few general problems in 

 connection with hot-air treatment. 



The first question which is always asked is " What temperature 

 kills the worm and what length of time is necessary ? " There seems to 

 be, however, a very general misapprehension as to what is meant by 

 a reply to this question. For instance, if one says that five minutes 

 at a temperature of 55 C. will kill all the worms, this does not mean 

 that if seed containing worms is placed in a hot-air chamber, the air 

 in which is at a temperature of 55 C., and left there for five minutes, 

 all the worms will be found dead at the ,end of that time. They 

 probably would not be. What it does mean is that if the worms 

 themselves are heated up to 55 C. and maintained at that temperature 

 for five minutes they will all be killed. The difficulty is that it is 

 impossible to determine the temperature of an individual worm at 



