Norton 16H flat tank

Easy to recognise this period snap as a Norton, more than likely a 16H and I would guess from 1925. Nicer composition than many amateur photos of the era.

Mid twenties flat tank Norton 16H.

postscript: 

Many thanks to John de Kruif of www.vintagenorton.com for identifying the Norton as in fact probably being from 1926 - it has heavier weight Druid forks introduced in that year though still sports a saddle from the 1925 model year.