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The Olavinich drier is essentially like the Bosanska in operation 
and construction except that metal piping for conveying combustion gases 
traverses the inner chamber several times before discharging" into the outer 
air. Near the top o£ the drying chamber small openings allow" the escape 
of moisture laden air. This system is thought to ha v e increased circulation 
sufficiently to secure about fifty per cent "hot air' 1 and fifty per cent 
"direct heat" . 
The Stoykovich drier is more scientifically designed. All heating 
is by "hot air" and ingress for cold air and outlet for used air insures 
ventilation. The longer inclined tunnel creates a natural draft. Lanier 
of fruit burning h r; s been reduced by placing the fire box some distance 
a- ay. The metal oven is placed in a 10 x 8.x 3 foot basement and metal 
pipes run through an 8x8x6 foot neater above the oven. The drying chamber 
or tunnel holds five racks and the racKs hold ten trays- This drier is so 
constructed that it can be used either continuously or separately. In 
the l&tter case, the fruit would have to be taken out at intervals as in 
the more primitive types, \7here used as a continuous type the fresh fruit 
is admitted at the upper end of the inclined 1 tunnel under a steadily 
ma i nt a ined t e mp e r ature of 50 degree s cent igr ade . Aft e r t en hour s a n ew 
lot of travs is introduced forcing the first lot toward the main heating 
chamber where. the temperature is £ept at 65 degrees centigrade, kfter the 
second ten hours a third lot of trays pushes the first lot just over the 
oven where they are held for ten hours at about 80 degrees centigrade. 
The introduction then of the fourth lot of travs forces out the original 
lot so the process is continuous. The agriC ilturel schools in Serbia 
have built Stoykovich driers as models for demonstration to. the peasants. 
At the 3elgrade prune conference in December 1926, it "'as ur^ed 
that the Government should provide credit with which to encourage the 
construction of modern cooperative driers and that a great deal of atten- 
tion should be given to demonstration courses in the buildin fe of modern 
driers. Such courses -ere held for the peasants at Cacak-soon after the 
'-an with excellent results, "hile many of the existing regulatory measures 
have been useless the above suggestions if followed out would remove many 
of the present objections to the quality of Yugoslav prunes- It is mani- 
festly useless to have prunes' harvested at the proper time only to be 
subjected to the primitive methods of drying described. 
