THE PRODUCTION OP MAPLE SIRUP AND SUGAR. 



35 



when having ;i concentration equal to 11 pounds to the gallon. It 

 is necessary, tlien. to note the boiling point of the sirup only in the 

 last pan to decide whether it is concentrated sufficiently. In taking 

 this temperature, one must be sure the thermometer is correct and also 

 that it does not touch the bottom or sides of the evaporator, but 

 measures the temperature- of the liquid only. 



When a thermometer is used, if the temperature which it regis- 

 ters when placed in the l>oiling water is noted, and 7 added to this, 

 the result will be the point at which the sirup boils when it is prop- 

 er! v concentrated. It is of extreme importance, however, to test the 



i-25 



FIG. lii. Hydrometer and its position in the liquid. 



sirup again by weighing a quart or a gallon of the same after it has 

 cooled to make sure that it has a proper density. 



By Baume hydrometer: A hydrometer or spindle is an instrument 

 for showing the density of a liquid. Hydrometers are graduated to 

 various scales and for various purposes. The one generally used for 

 rough sugar work is the Baume. The standard of graduation is an 

 arbitrary one and varies somewhat with different makes. The usual 

 Baume hydrometer is made of glass and shows a graduation from 

 zero to 50, divided into degrees, as shown in figure 12. The density 

 is measured by floating the hydrometer freely in the liquid, which is 

 generally held in a tall cylinder, as shown in the illustration. The 

 510' 



