28 



THE PRODUCTION OF MAPLE SIRUP AND SUGAR. 



The iron kettles are generally from 2 to 4 feet in diameter and are 

 seldom housed. They are set on stones, as shown in figure 8, or sus- 

 pended from a support. In some cases two or more are set in brick- 

 work, with the place for the fire underneath. This form of evapora- 

 tion apparatus is the crudest and seldom, if ever, yields a pleasant- 

 tasting product. The danger of burning or scorching the sirup by 



the flames playing 

 around the metal near 

 the edge of the liquid 

 is ever present. 



Another crude meth- 

 od of boiling is with 

 sheet-iron pans, gener- 

 erally from 2 to 3 feet 

 wide and 3 to 6 feet 

 long. They are raised 

 above the ground by a 

 brick or stone work 

 and the fire built under 

 them. The same objec- 

 tion can be raised to 

 them as to kettles, 

 namely, the danger of 

 scorching the sirup. 

 They are, however, a 

 step toward a better 

 product. Many makers 

 use pans made of sheet 

 tin or galvanized iron. 

 The former, with care 

 in boiling, can produce 

 a good -flavored prod- 

 uct, but those of gal- 

 vanized iron can not be 

 recommended. Figure 

 9 shows such home- 

 made pans in place. 

 In this case there are 

 two pans, one back of 

 the other. The sap 

 can be placed in the 

 front pan and when 

 partially concentrated be transferred to the back one or vice versa by 

 means of a ladle. The figure shows also the brick masonry consti- 

 tuting the arch. Because of this arrangement this form of concen- 

 trating apparatus is generally known as an arch evaporator. In 

 most cases the arch is constructed of brick, but quite often stone is 

 used. It may be 3 to 4 feet wide and from 8 to 15 feet long, inside 

 measurements. The sides are generally from 2J to 3 feet high. 

 Between these two walls the bottom is bricked or cemented and the 

 walls are held together and in place by iron stays, which also 

 serve to hold or support the pans. At the back the arch ends in 



516 



FIG. 9. Arch with metal pans for evaporation ; storage 

 tank for sap in rear. 



