PROCEEDINGS OF THIRTY-SIXTH FRUIT-GROWERS ' CONVENTION. 143 



Under the third head, methods based upon mixing or stirring the 

 air, no special devices that are available and practicable are known. 

 When nature mixes the air, i. e., on windy nights, frost does not occur. 

 IT is now known to meteorologists that layers of air of different tem- 

 perature may lie close to one another without mixing. On nearly every 

 frosty night* there is a difference of 6, 8 or 10 degrees in temperature 

 between the ground and the air ten feet above, the warmer layers 

 being above. Where air is well mixed and there is good ventilation, we 

 seldom find frost. 



Finally, in our opinion the ideal frost protection method will be a 

 combination of a cover, a heater and a ventilator, and if the views 

 advanced at the beginning of this paper are correct, as to injury caused 

 by desiccation, it will also be necessary to provide for water in proper 

 quantity. 



To sum up, the fruit groAver should: 



1. ^Vatch the weather forecast closely. 



2. Study local air circulation. 



3. Use a thermograph in the orchard and study the temperature 

 record. 



4. Experiment and determine for his particular crop the most suit- 

 able heater, cover or watering device. 



5. Do not give up the fight against frost, because of a first failure. 



PRESIDENT JEFFREY. We will now have the pleasure of hear- 

 ing from Mr. Arthur R. Briggs. the President of the State Board of 

 Trade, upon the subject of "Sulphuring Fruit." 



SULPHURING FRUIT. 



By Arthur R. Briggs of San Francisco. 



Mr. Chairman. Members of the Fruit Growers' Convention, Ladies 

 and Gentlemen : It is always a bad plan for one to make excuses, but 

 private matters have been thrown upon me during the last month to 

 such an extent that I found it necessary to digress somewhat from the 

 program that the Chairman had made out, namely. I was set down for 

 a paper on the sulphur question, and that paper is in my mind rather 

 than in my hand. If I was as good a talker as Colonel Irish, who has 

 just preceded me. I pledge you I would not work for a living. 

 Fortunately for me this morning, he has paved the way for me by 

 telling of the great industry which you are considering, its importance 

 to the State, and Avhat should be done with it. He has left for me 

 merely the prosaic portion of the work — that is. to tell something of 

 the history of the sulphur question and its present status. 



You are doubtless all aware that the Federal Pure Food law was 

 passed in June. 1907. You are also aware what consternation was felt 

 in California among the fruit growers when the first decision, known 

 as the food inspection decision Xo. 76. was issued by the federal 

 department. That order Avas issued by a commission constituted by 

 the law itself, which commission was composed of three cabinet officers, 

 namely, the Secretary of Agriculture, the Secretary of Commerce and 

 Labor, and the Secretary of the Treasury. Two of these officers knew 

 nothing of the fruit business, knew nothing of the effect the order 



