“So you gotta add three of the bifenthrin to one,” Mr. Taggart said. He patted Buck on the back, one hand lingering there over his shoulder muscle. “That gives you nine.”
Buck had no idea what that meant, but it was how Mr. Taggart talked. It was confusing because he mixed up units of measure that he assumed Buck remembered — some pesticides were measured in liters, while others were measured in gallons, or fluid ounces, and some came already diluted or not at all, and further, some additives (like surfactants) were measured in milliliters or fractions of a pint or quart.
Regardless of the official formulas provided by the pesticide manufacturer, the tanks in the truck were built to measure their output in fractions of liters or gallons, depending on the tank. So when Mr. Taggart said, “fill that tank to the two over three, that’ll take ten of the other, then just one more is four, plus three of the surfactant”, what he actually meant was “use that tank that has lines measuring its fill in gallons, and fill it with ten liters of pesticide, which will equal two and two-thirds gallons, then dilute it with one and a third gallons of water to get near four gallons total, which requires three fluid ounces of surfactant”.
It was very confusing. Every time Buck thought he had a handle on it, Mr. Taggart would say something like, “okay, for mosquitoes we need nine five-eighths of the crimpoline mixed with three and a quarter half-gallons of the geraniolic acid”. Yes, that’s right, he measured a formula using “nine five-eighths” (meaning nine units each equal to five eighths of a liter) to mix it with a volume measured in quarters of a half-gallon. He expected Buck to calculate how many quarters-of-a-half-gallon could be combined with some number of five-eighths-of-a-liter to result in a fourteen-liter total volume.
To make matters even more confusing, the formula to calculate how much to spray for mosquitoes gave a result in fluid ounces of the undiluted pesticide. To be more precise, it gave a result in fluid ounces per square meter, so Buck had to calculate the acreage of each property in square meters then combine pesticides in gallons and liters to convert, using the diluted density, into an amount of pesticide per fluid ounce, modified with surfactants by the droplet surface area in cubic millimeters, in order to calculate how much to fill the tank with.
Buck had never really been a math guy in school. He hadn’t even graduated.