UPRIGHT DRIERS 87 



from the basement passes over the heated surfaces and ascends 

 through the shaft, drying the fruit as it rises and carrying the 

 vapors into the atmosphere. The fruit is placed in the stack on 

 the first floor, that is, the floor above the basement. It is spread 

 on trays, and as new trays are put in, those which were first in- 

 serted are elevated in the tower. The trays finally reach the 

 second story, by which time the fruit should be finished, and the 

 trays are removed and emptied and taken back to the first floor, to 

 be used again. This, in brief, is the principle upon which the 

 tower evaporators work, but there are endless variations in the 

 details, to some of which we must now direct our attention. 



"The first stacks were built of wood. In 1881, L. R. Rogers, 

 son of Mason L. Rogers, to whom I have already introduced the 

 reader, built stacks of brick from the basement to the top of the 

 drying chamber in the second story. This was on the old home- 

 stead near Williamson. A year or two after this, W. H. Bush, of 

 Marion, built brick -stacks from cellar to cupola, and such stacks 

 are now frequently seen. The advantages of the brick- stacks are 

 durability and safety from fire. The greatest danger of fire is 

 inside the stack, and the wooden fittings and trays of these brick 

 towers could burn out without setting fire to the building. It is 

 the common practice to build the stack inside the building, chiefly 

 because it is a prevailing opinion that the wind interferes with the 

 draft if the stack is built against the building and exposed on 

 three sides. This opinion is held in respect to brick stacks, in 

 particular, for it is thought that the air will draw through the 

 brick walls, and that they will also become damp in stormy 

 weather, if exposed. This notion appears to be unfounded, how- 

 ever, for W. H. Bush, of whom I have spoken, has recently 

 erected a most successful establishment at his new home at Wal- 

 worth, with three outside brick stacks with four-inch walls. Mr. 

 Bush has had much experience in the evaporating business, and as 

 I consider his new outfit to be a model in its way, I shall have 

 much to say about it later on. (See Figs. 16, 17, 19, 20, 21, 

 22,23.) 



" The interior of one of these stacks must now be seen . We 

 will first turn our attention to the basement or foundation of Mr. 



