The first one appears to be a basic hydrometer with one scale that reads from 980 to 1130 and a second labeled as "Alcoholic Strength after fermentation" with a scale that reads from 4 down to 18. How is this second scale read? It also is written above the scale "1700 grams of sugar per hectoliter produce 1 degree of alcohol" What exactly does this mean??The second Herter's MUSTIMETER is the same as the first AND also has a thermometer in it with a range from 20 degrees to 120 degrees. I'm assuming that is in degrees Fahrenheit and not Celsius. Then to the right of the degree markings and the actual thermometer itself is another scale in read that runs from the top marking starting at 4.0 - 3.1 - 2.2 - 1.5 - 0.7 - 0 - 0.7 - 1.1 - 1.4 - 1.7 - 2.0 with the following "Above 0 add, below 0 subtract - As many tenths as indicated by Figures"
I understand the Specific Gravity side of things, but I'm not sure about the "Alcoholic Strength after fermentation" scale. What does the scale of 4 down to 18 stand for? On the "Above 0 add, below 0 subtract" scale. I think that has something to do with some sort correction due to temperature?
Thanks for any help.