a 1 in 8


I can’t understand the meaning of phrase “a 1 in 8” in a extract about a guy who rents a horse caravan to explore Ireland. I’d appreciate your help.

… Probably the most important lesson is to keep to the route you are given. Take it from me, horse caravans and hills do not a good mix make. On the final leg, I took a wrong turning and we found ourselves slipping and sliding down a 1 in 8. I had no alternative but to find a turning place and then put my back into helping the horse back up the hill again. But that, as they say, is all part of the fun.

It is not a familiar turn of phrase to me, but it is evidently a slope ratio: the slope descends one foot in every 8 feet of horizontal distance.

Thank you.