Jones's Rule of 86

Charles Howland Jones came to Vermont in 1896 from Massachusetts and "virtually yanked the maple tree out of the sixteenth century." Known as C.H. to his friends and colleagues, he "attacked the controversies and mysteries of sap flow head-on. If you recently participated in our Trivia Contest, you'll appreciate reading about Jones's Rule of 86, which helps you calculate the amount of maple sap required to make a gallon of pure maple syrup.

"Jones's paper, "The Carbohydrate Contents of the Maple Trees," was a scientific tour de force, but Jones would be remembered most for a curious calculation he devised as a result of this work. His various talents came together in a clever statement of the relationship of sugar content in maple sap to the amount of syrup a given amount of sap will produce. Jones explained to sugarmakers that if the percent of sugar is known and used to divide into the constant 86, the number of gallons of sap needed to produce one gallon of finished syrup would be known. Thus sap with a concentration of 2 percent would dictate a total of 43 gallons of sap to produce one gallon of syrup."

"Eighty-six is really a factor to use as a shortcut for some pretty involved chemical calculations," says Lighthall. "It is based on some very precise measures of the density of weak sugar solutions." Jones, however, made it all seem rollickingly simple by spinning out the rule in doggerel that is still tacked up on beams in sugarhouses throughout New England." 

(We've tried to track down the rule in doggerel supposedly posted in sugarhouses and have found no trace, so far! Does anyone know it?)

Source: James M. Lawrence and Rux Martin, Sweet Maple: Life, Lore and Recipes from the Sugarbush, Chapters Publishing Ltd. and Vermont Life Magazine: Vermont, 1993.