OK, so that's about 50 feet per gallon, using imperial gallons instead of US gallons (assuming they used dry gallons rather than wet ones). Hmmm. Maybe it's be

OK, so that's about 50 feet per gallon, using imperial gallons instead of US gallons (assuming they used dry gallons rather than wet ones). Hmmm. Maybe it's better to say 1.5 chains to the peck to avoid confusion over the different gallons.