DISCUSSION OF MANUFACTURING DATA, 53 



THREE KINDS OF EVAPORATING APPARATUS. 



The storage tanks at the evaporation houses were wooden in over 

 50 per cent of the cases and metal in the others, with a capacity 

 varying from 100 to 400 gallons. The evaporation equipments 

 observed may be divided into three general classes: (1) Iron kettles 

 or pans; (2) arch evaporators; (3) patent evaporators. 



Iron kettles or pans. The camps equipped with kettles or pans 

 generally boiled in the open in kettles from 2 to 4 feet in diameter, 

 placed as previously described, while a few used iron pans, in which 

 | the fire box was dug out of the ground and sometimes bricked up 

 j on the sides of the pit, with a row of bricks on top of the ground. 

 The pans generally were 2 by 3 or 3 by 6 feet and rested on this layer 

 of bricks. Some of the largest makers used a few iron pots in connec- 

 tion with their evaporators, but these were only employed in an emer- 

 gency to handle an extra heavy run of sap. 



Arch evaporators. In all cases this outfit was placed in a shed. 

 The evaporator itself was a pan, generally of sheet. iron, or in a few 

 eases two or more pans on the same arch, which were placed on two 

 rows of brick or stone walls about 4 feet apart, 3 feet high, and from 

 8 to 15 feet long. At one end a chimney of the same material was 

 erected, just clearing the roof. The pans fitted on top of the walls 

 and formed an arch, hence the name "arch evaporators.'' In the 

 majority of cases the brick or stone walls were of loose construction, 

 with mud between the cracks and crevices, so that smoke quite often 

 issued from the numerous holes. Generally the front of the arch was 

 covered with a piece of sheet iron, or in some cases w r ith a regular 

 ^alvanizod-iron front having doors. 



Patent evaporators. Many forms of patent evaporators were found 

 in use, some of which were more common than others. Generally 

 they consisted of a heavy iron arch or fire box from 3 to 4 feet wide 

 and from 10 to 15 feet long, open on top, with a stack at one end 

 and the fire and ash doors at the other. Some of the evaporators 

 were as large as 6 by 24 feet. Fitted on top of this compact iron 

 furnace or arch were the pans of tin plate divided into compart- 

 ments, and in some cases on the back toward the chimney were several 

 separate small pans in which the product was finished. Some had 

 an apparatus for automatic feeding on the side, which also main- 

 tained a constant level. The sap entered there and ran a zigzag 

 course over the fire, siphons being used to pass the sirup over the 

 walls. 



In some sections a large number of makers used either the arch or 

 patent evaporators, but it was a mooted question as to which of the 

 two produced the better sirup; that is, one of lighter color and more 

 pleasant flavor. Beyond doubt the patent evaporators have all 



