TWENTIETH ANNUAL MEETING. 93 



THE FIRST LAEGE EVAPOEATOR. 



The first to build on a large scale was Alden. Doubtless you are all 

 familiar with this evaporator. It consisted of a tower about four feet 

 square on the inside, built from the basement through a two-story build- 

 ing, and out at the top like a huge chimney. Steam radiators were first 

 used but did not give satisfaction; then hot air from a furnace in the base- 

 ment passed up through the fruit. The apples were put on thirty or forty 

 trays, the one over the other, the fresh apples being put in near the ceil- 

 ing of the second floor and gradually lowered to near the floor of the first 

 story, where they were taken out. This seemed to be the most philosoph- 

 ical method, but experience told difPerently. The fruit was badly scorched 

 when brought near the furnace in a nearly dried condition. The process 

 was reversed and proved more satisfactory. His device for raising was an 

 endless chain, and as often as a tray of fresh apples was introduced at the 

 bottom a tray of dried ones was taken out at the top. 



This type of evaporator came out with a great many variations, and with 

 as many different devices for raising the trays, all depending on the hot 

 air currents through the apples for carrying off the moisture. Alden 

 claimed that his patent covered the use of hot air in that way and com- 

 menced litigation to sustain his rights. A combination contested his 

 claim; the struggle continued several years and finally resulted in his 

 defeat. 



In the first evaporators, slats of wood were used for the trays, then 

 common iron wire; but that would rust quickly and mark the apples. 

 This brought about the use of galvanized iron wire, of which so much has 

 been said of late on account of Germany and Holland destroying several 

 large consignments of evaporated apples in which traces of lead and zinc 

 were found. After this they refused to receive apples unless accompanied 

 by certificate that they were free from any traces of poison. This is a 

 matter that should demand the attention of this society in its discussions. 

 Horizontal evaporators have been in use for some time, with natural or 

 forced currents of heated air. They were brought into favor during the 

 late war and were used in preparing desiccated vegetables for the soldiers, 

 to keep off scurvy. 



USE OF STEAM. 



As stated before, steam radiators were used in the first Alden towers. 

 Many others tried steam in a small way, but it was not at all satisfactory. 



Of late, however, it has come into favor and is used very largely in a 

 different manner, the heat being diffused among the trays by means of a 

 system of steam pipes. The results are so satisfactory that steam will 

 soon be used in most of the large factories. In fact, the indications are 

 that the old hot-air tower will be superseded and soon become a thing of 

 the past. Some of the advantages of steam are that the evaporator is more 

 compact and on one floor. Steam can be used from a mill or factory after 

 having been used in other work, the dead steam being worth 90 per cent, 

 of live steam. Where a good supply of steam so used can be obtained, it 

 makes the heating of the evaporator cost very little indeed. A third 

 advantage in using steam consists of passing it from the evaporator through 

 the work-rooms for warming purposes. 



There are already many claimants for public favor in the field, with 



