Which preposition to use with towpath
" Mr. Sharp said that so long as he pleased her nothing else mattered, and, in the seventh heaven of delight, paced slowly along the towpath by her side.
Satisfied of this, he lit his pipe and stood for a minute puffing at it, and staring, now at the stagnant canal water, now after the retreating figures of Miss Sally and Mr. Hucks, as without a backward look they passed down the towpath to the Iron Bridge.
His next business was to fetch a horse from the stables at the Canal End and tow the boat back to her quarters; and having taken another glance around, he set off and up the towpath at a pretty brisk pace.
It stood, in fact, just beyond the bridge, with a high brick wall that turned off the street at right angles and overhung the towpath of the canal.
Nor did he betray surprise when Mr. Mortimer, after a glance down the towpath towards the iron bridge and the tram-lights passing there, walked off and left him to browse.
As Tilda hobbled towards him he hoisted the full bucket on his shoulders, staggered across the towpath with it, and shot its contents into a manhole under the brick wall.