538 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



that " it is the fastest, and for its capacity the most economical, 

 evaporator offered for sale." 



The other form of evaporator I shall describe differs from 

 the Zimmerman and others of the same general pattern in the 

 arrangement of its hot-air chamber, which is not placed vertically 

 above the stove, as is the case in those already described, but at 

 a small angle in an inclined position, away from the stove or 

 furnace. This, which is known as the "American" evaporator, 

 is made at Waynesboro', Franklin County, Pennsylvania, by the 

 American Manufacturing Company ; also by Messrs. Ph. Mayfarth 

 ■& Co. at Frankfort-on-the-Main, who have an agent in England, 

 Mr. A. Ludwig, 16 Mincing Lane, London. A sketch of this 

 evaporator is given in fig. 3G. These are the terms in 

 which the American Manufacturing Company describe the merits 

 of their evaporator: — " By a process contrary in effect to that 

 so long practised faut de mieux by the old-school dryers, we, by 

 the direct action of heat in the primary stages, fix the essential 

 oils to which aroma and flavour are due. At the same time, by 

 the action of the automatically diffused currents of hot dry air, 

 is developed an artificial cuticle or parchment-like skin, and thus 

 hermetically sealing the cellular formation containing the volatile 

 essential oil, on the perfect retention of which so much depends. 

 . . . By our method we likewise prevent any retrograde effects, 

 for the operation is continuous to the finish, which takes effect 

 at a reduced graduated point of temperature, and, while the 

 automatic discharge, seriatim, of waste vapouric elements is 

 effectually provided for, we likewise insure a succession of currents 

 of fresh dry hot air, which automatically pass underneath, diago- 

 nally through,. and then off over" the trays inside the " inclined 

 pneumatic flue." It is claimed that the action of the evaporator 

 is so rapid that the exposure of green fruit for ten minutes only 

 in the hot-air chamber is sufficient to perfectly dry it on the 

 outside. The currents of hot air passing through this evaporator 

 when in full work are said to be " self-created and continuous, 

 strike the trays at a uniform upward angle with considerable 

 velocity, quickly absorb all moisture, then pass off out of the 

 evaporator." The " American " is made in a number of 

 sizes. The smallest, No. 0, is made for family use or limited 

 operations only ; price at the works, £1. 10s. No. 1 has a 

 surface drying capacity of 85 -square feet, and the price is 



