What country is this likely to be - England ?
Having the magneto behind the engine like that is fairly unusual, certainly in the 1907ish-1910/11 time span that this bike is going to be from.
The letters on the magneto chain cover look to be EMA, maybe someone can shed some light on that, or what they actually are.
Great pic, motorcycling back then was a real adventure, so your grandad was a seriously serious enthusiast. !!